Lewis diagrams

WEBVTT
Kind: captions
Language: en

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- [Instructor] In this video,

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we're gonna introduce
ourselves to a new way

00:00:03.270 --> 00:00:05.100
of visualizing atoms.

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And as you can imagine
from the title here,

00:00:06.930 --> 00:00:09.570
that's going to be Lewis diagrams.

00:00:09.570 --> 00:00:11.310
But before I even get into that,

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let's do a little bit of
review of what we already know

00:00:13.710 --> 00:00:15.450
about Bohr models.

00:00:15.450 --> 00:00:18.570
So let's say we take an
arbitrary element here.

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Let's say we take nitrogen.

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Nitrogen, by definition,
has seven protons.

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And so if it's neutral, it's
going to have seven electrons.

00:00:26.040 --> 00:00:28.740
So a Bohr model for nitrogen,

00:00:28.740 --> 00:00:31.860
in our first shell, that
first shell is going to look

00:00:31.860 --> 00:00:35.700
just like helium and it's
going to have two electrons.

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So let me draw it like that.

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And then in its second shell,

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its second shell, it is going
to have the remaining five

00:00:45.840 --> 00:00:47.880
of the seven electrons.

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And we are going to make
them unpaired at first.

00:00:50.220 --> 00:00:52.590
So one, two,

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three, four, and then five.

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The reason why I did it this way is,

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a full valence shell is
going to have eight electrons

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or four pairs.

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But if the electrons can spread apart,

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they like to spread apart.

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So that's why I did one, two, three, four,

00:01:08.520 --> 00:01:11.190
and then I paired this last one
because there's nowhere else

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for it to actually go.

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Now, I just touched on this
issue of valence electrons.

00:01:16.530 --> 00:01:18.750
Those are the electrons
in your outermost shell,

00:01:18.750 --> 00:01:22.680
and they tend to be the ones
that are involved in reactions.

00:01:22.680 --> 00:01:24.840
So chemists said, "Hey,
just for shorthand,

00:01:24.840 --> 00:01:27.420
instead of having to draw
all of this every time,

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why don't we just visualize
the valence electrons?"

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And so let's do that in
this nitrogen example.

00:01:34.590 --> 00:01:37.590
So a Lewis diagram,

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which is I'm just going to draw right now,

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is that simplified visualization

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where you write the
symbol for that element,

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and you just depict its valence electrons.

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We just saw that there
are five valence electrons

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for nitrogen, seven
total, but five valence,

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five electrons in that outermost shell.

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So it is going to be one, two,

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three, four, and then five.

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So that's a Lewis diagram
for a neutral nitrogen atom.

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It turns out we can also do this for ions.

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So let's say that we had
a nitride ion over here.

00:02:15.870 --> 00:02:19.020
Now, a nitride ion has
gained three electrons.

00:02:19.020 --> 00:02:21.810
So it actually has
eight valence electrons.

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So if you gain three from five,
you're going to have eight.

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So I'll go one, two,

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three, four, five,

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six, seven, eight.

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And because it gained three
electrons from being neutral,

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it now has a negative three charge.

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And so you'll often see
it written like this

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where they put brackets around it,

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and you would see three minus.

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Now, the last thing that
you might wonder about is,

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"Okay, I kinda understood

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how you got the valence
electrons for nitrogen.

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Is there just some general
pattern in the periodic table?"

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And the simple answer is yes.

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And that's one of the useful things

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about the periodic table.

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Or as we'll learn,
there's many, many other

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really interesting things about it.

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If you look at the groups, in general,

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you're going to have one valence electron

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for Group One elements,
for this column over here.

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You're going to have two valence electrons

00:03:13.680 --> 00:03:15.630
for these Group Two elements.

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And I know what you're thinking,

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"Okay, is just the group the
number of valence electrons?"

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Well, unfortunately, it doesn't
exactly work out that way.

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I'm going to skip the
transition metals here

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because those get a little
bit more complicated.

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It's a little bit more advanced.

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But then if we go over
here to, what is this,

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Group One, Two, Three,
Four, Five, Six, Seven,

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Eight, Nine, 10, 11, 12, 13,

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Group 13 over here is going to
have three valence electrons.

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Group 14, four valence electrons.

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Five valence electrons in Group 15,

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and that's why we saw
five valence electrons

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for nitrogen here.

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Six for Group 16.

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Seven for Group 17.

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And then 18 for, or sorry, (laughing)

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I should say eight valence
electrons for Group 18.

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So one way to remember it is,

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for Groups 13 through 18,

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you take the group number
and you subtract 10,

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and you're going to get the
number of valence electrons.

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And hopefully that made sense based

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on how we were able to figure
out the valence electrons

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for example nitrogen.


Atomic spectra

WEBVTT
Kind: captions
Language: en

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- [Narrator] Here's a very
simplified model of an atom.

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The nucleus at the center of
the atom is where the protons

00:00:06.180 --> 00:00:09.900
and neutrons live, but
they're kind of boring

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because for the most
part, they just sit there.

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The real star of the show is the electron.

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The electron gets to do
all the interesting stuff

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like move around, jump
around, bind with other atoms.

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These dashed lines represent
the different energy levels

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the electron can have while in the atom.

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We like representing these energy levels

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with an energy level diagram.

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The energy level diagram
gives us a way to show

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what energy the electron has
without having to draw an atom

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with a bunch of circles all the time.

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Let's say our pretend atom
has electron energy levels

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of 0 eV, 4 eV, 6 eV, and 7 eV.

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Note that moving left or right

00:00:51.090 --> 00:00:52.740
on an energy level diagram

00:00:52.740 --> 00:00:55.890
doesn't actually represent
anything meaningful.

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So technically there is no X axis

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on an energy level diagram,
but we draw it there anyway

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because it makes it look nice.

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All that matters is what energy level

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or rung on the ladder the electron is at.

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Note that the electron

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for our hypothetical
atom here can only exist

00:01:13.020 --> 00:01:16.320
with 0 eV, 4, 6 or 7 eV.

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The electron just cannot
exist between energy levels,

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it's always got to be right
on one of the energy levels.

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Okay, so let's say our electron starts off

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on the 0 eV energy level,

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it's good to note that
the lowest energy level

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and electron can have in an
atom is called the ground state.

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So how could our electron
get from the ground state

00:01:37.320 --> 00:01:39.330
to any of the higher energy levels?

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Well, for the electron to
get to a higher energy level,

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we've got to give the
electron more energy,

00:01:45.270 --> 00:01:47.520
and we know how to give
an electron more energy,

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you just shoot light at it.

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If a photon of the right
energy can strike an electron,

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the electron will absorb
all the photon's energy

00:01:55.710 --> 00:01:57.840
and jump to a higher energy level.

00:01:57.840 --> 00:02:01.020
The electron in this
ground state needs 4 eV

00:02:01.020 --> 00:02:03.300
to jump to the next energy level.

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That means if a photon that
had an energy of 4 eV came in

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and struck the electron,

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the electron would absorb the energy

00:02:10.860 --> 00:02:13.984
of the photon causing
the photon to disappear,

00:02:13.984 --> 00:02:17.880
and that electron would jump
up to the next energy level.

00:02:17.880 --> 00:02:21.060
We call the first energy
level after the ground state,

00:02:21.060 --> 00:02:23.310
the first excited state,

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once the electrons at
the higher energy level,

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it won't stay there long
electrons, if given the chance,

00:02:29.310 --> 00:02:32.310
will fall towards the lowest
energy level they can.

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So our electron will fall
back down to the ground state

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and give up 4 eV of energy.

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The way an electron can give up energy is

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by emitting a photon.

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So after falling back
down to the ground state,

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this electron would emit a 4 eV photon.

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Electrons don't have to
just jump one energy level

00:02:51.068 --> 00:02:52.770
at a time, though,

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if the electron in our ground state were

00:02:54.780 --> 00:02:57.300
to absorb a 6 eV photon,

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the electron can jump all the way up

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to the 6 eV energy level.

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Now that the electron's
at a higher energy level,

00:03:03.600 --> 00:03:05.700
it's gonna try to fall back down,

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but there's a couple ways
it could fall back down

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in this case.

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The electron could fall down

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to the ground state all in one shot,

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giving up a 6 eV photon in the process.

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But since the started at
the 6 eV energy level,

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it could have also fallen first

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to the 4 eV energy level
emitting a 2 eV photon

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in the process.

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It's a 2 eV photon

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because the electron dropped
2 electron volts in energy,

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and now that the electron's
at the 4 eV energy level,

00:03:36.780 --> 00:03:37.980
it'll fall back down

00:03:37.980 --> 00:03:42.210
to the ground state emitting
a 4 eV photon in the process.

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So electrons will sometimes
drop multiple energy levels

00:03:45.300 --> 00:03:46.230
at a time,

00:03:46.230 --> 00:03:49.293
and sometimes they'll choose
to take individual steps,

00:03:49.293 --> 00:03:52.950
but regardless, the energy
of the photon is always equal

00:03:52.950 --> 00:03:55.830
to the difference in
electron energy levels.

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What if our electron's in the ground state

00:03:57.660 --> 00:04:00.270
and we send a 5 eV photon at it?

00:04:00.270 --> 00:04:02.910
If the electron were to
absorb all of the energy

00:04:02.910 --> 00:04:04.740
of the 5 eV photon,

00:04:04.740 --> 00:04:07.260
it would now have 5 electron volts,

00:04:07.260 --> 00:04:09.270
but that's not an allowed energy level

00:04:09.270 --> 00:04:11.457
so the electron can't absorb this photon

00:04:11.457 --> 00:04:14.310
and the photon will pass
straight through the atom.

00:04:14.310 --> 00:04:16.200
Keep in mind, the electron in the atom has

00:04:16.200 --> 00:04:19.380
to absorb all of the photon's
energy or none of it,

00:04:19.380 --> 00:04:21.390
it can't just absorb part of it.

00:04:21.390 --> 00:04:24.570
Alright, so now we could figure
out every possible photon

00:04:24.570 --> 00:04:26.190
this atom could absorb.

00:04:26.190 --> 00:04:28.050
If the electron's in the ground state,

00:04:28.050 --> 00:04:32.220
it could absorb a 4 eV
photon or a 6 eV photon

00:04:32.220 --> 00:04:34.200
or a 7 eV photon.

00:04:34.200 --> 00:04:36.510
If the electron's at
the second energy level,

00:04:36.510 --> 00:04:38.850
also called the first excited state,

00:04:38.850 --> 00:04:41.460
the electron could absorb a 2 eV photon

00:04:41.460 --> 00:04:43.680
or a three eV photon,

00:04:43.680 --> 00:04:46.170
and if the electron were
at the third energy level

00:04:46.170 --> 00:04:48.450
or the second excited state,

00:04:48.450 --> 00:04:51.330
the electron could absorb a 1 eV photon.

00:04:51.330 --> 00:04:52.950
Those are the only photons

00:04:52.950 --> 00:04:56.160
that this atom will be seen to absorb.

00:04:56.160 --> 00:04:59.700
2.5. eV photons will
pass straight through,

00:04:59.700 --> 00:05:02.400
5 eV photons will pass straight through,

00:05:02.400 --> 00:05:06.300
6.3. eV photons will
pass straight through.

00:05:06.300 --> 00:05:09.030
What this means is that
if you were to shine light

00:05:09.030 --> 00:05:12.510
that consisted of all possible
wavelengths through a gas

00:05:12.510 --> 00:05:15.180
that was composed of our pretend atoms,

00:05:15.180 --> 00:05:17.670
all the wavelengths would
not make it through.

00:05:17.670 --> 00:05:19.770
Some of the wavelengths
would get absorbed,

00:05:19.770 --> 00:05:22.710
then scattered away in random directions.

00:05:22.710 --> 00:05:26.820
This would manifest itself as
dark lines in the spectrum,

00:05:26.820 --> 00:05:29.550
missing wavelengths or
missing energy levels

00:05:29.550 --> 00:05:32.460
that correspond to the energies of photons

00:05:32.460 --> 00:05:34.290
that our electron can absorb.

00:05:34.290 --> 00:05:36.750
This is like a fingerprint for an atom,

00:05:36.750 --> 00:05:40.230
and it's called that
atom's absorption spectrum.

00:05:40.230 --> 00:05:42.090
If you were to ever see this progression

00:05:42.090 --> 00:05:45.390
of dark lines in these exact
positions, you would know

00:05:45.390 --> 00:05:47.760
that the gas you were
looking at was composed,

00:05:47.760 --> 00:05:50.670
at least partly of our hypothetical atom.

00:05:50.670 --> 00:05:52.980
This also allows astronomers to determine

00:05:52.980 --> 00:05:55.140
what stuff in our universe is made out of.

00:05:55.140 --> 00:05:58.260
Even though we can't get close
enough to collect a sample,

00:05:58.260 --> 00:06:01.260
all we have to do is collect
light from a distance star

00:06:01.260 --> 00:06:04.770
or quasar that shines through
the stuff we're interested in,

00:06:04.770 --> 00:06:06.690
then just determine which wavelengths

00:06:06.690 --> 00:06:08.910
or energies got taken out.

00:06:08.910 --> 00:06:10.920
The details are a little
messier than that,

00:06:10.920 --> 00:06:12.390
but this provides astronomers

00:06:12.390 --> 00:06:15.900
with maybe the most important
tool at their disposal.

00:06:15.900 --> 00:06:18.780
Now, the absorption spectrum
are all of the wavelengths

00:06:18.780 --> 00:06:21.660
or energies that an atom
will absorb from light

00:06:21.660 --> 00:06:23.280
that passes through it.

00:06:23.280 --> 00:06:26.196
You could also ask about
the emission spectrum.

00:06:26.196 --> 00:06:29.070
The emission spectrum are
all of the wavelengths

00:06:29.070 --> 00:06:31.380
or energies that an atom will emit

00:06:31.380 --> 00:06:34.800
due to electrons falling
down in energy levels.

00:06:34.800 --> 00:06:36.570
You could go through all the possibilities

00:06:36.570 --> 00:06:38.490
of an electron falling down again,

00:06:38.490 --> 00:06:41.160
but you'd realize you're gonna
get the exact same energies

00:06:41.160 --> 00:06:43.170
for the emission spectrum that you got

00:06:43.170 --> 00:06:45.240
for the absorption spectrum.

00:06:45.240 --> 00:06:48.300
So instead of letting light
pass through a gas composed

00:06:48.300 --> 00:06:51.660
of your hypothetical atoms,
let's say you made a container

00:06:51.660 --> 00:06:53.730
that had the gas of
your hypothetical atoms

00:06:53.730 --> 00:06:55.710
and you ran an electric
current through it,

00:06:55.710 --> 00:06:58.380
exciting those electrons
to higher energy levels

00:06:58.380 --> 00:07:01.770
and letting them fall back
down to lower energy levels.

00:07:01.770 --> 00:07:04.200
This is what happens in neon lights,

00:07:04.200 --> 00:07:05.640
or if you're in science class,

00:07:05.640 --> 00:07:08.640
it's what happens in gas discharge tubes.

00:07:08.640 --> 00:07:10.440
So for the emission spectrum, instead

00:07:10.440 --> 00:07:12.780
of seeing the whole
electromagnetic spectrum

00:07:12.780 --> 00:07:16.140
with a few lines missing, you're
going to only see a handful

00:07:16.140 --> 00:07:19.500
of lines that correspond to
the energies of those photons

00:07:19.500 --> 00:07:21.123
that that atom will emit.


The mole and Avogadro's number

WEBVTT
Kind: captions
Language: en

00:00:00.780 --> 00:00:01.650
- [Narrator] In a previous video,

00:00:01.650 --> 00:00:06.650
we introduced ourselves to the
idea of average atomic mass,

00:00:06.960 --> 00:00:09.900
which we began to realize
could be a very useful way

00:00:09.900 --> 00:00:13.080
of thinking about a
mass at an atomic level

00:00:13.080 --> 00:00:15.360
or at a molecular level.

00:00:15.360 --> 00:00:16.920
But what we're gonna do in this video

00:00:16.920 --> 00:00:19.920
is connect it to the masses
that we might actually see

00:00:19.920 --> 00:00:20.760
in a chemistry lab.

00:00:20.760 --> 00:00:22.740
You're very unlikely to just be dealing

00:00:22.740 --> 00:00:26.100
with one atom or just a few
atoms or just a few molecules.

00:00:26.100 --> 00:00:28.560
You're more likely to
deal with several grams

00:00:28.560 --> 00:00:30.360
of an actual substance.

00:00:30.360 --> 00:00:33.840
So how do we go from the
masses at an atomic scale

00:00:33.840 --> 00:00:38.840
to the masses of samples

00:00:39.090 --> 00:00:41.700
that you see in an actual chemistry lab

00:00:41.700 --> 00:00:45.600
or in, I guess, you could
say our scale of the world?

00:00:45.600 --> 00:00:47.310
Well, the chemistry community has come up

00:00:47.310 --> 00:00:49.050
with a useful tool.

00:00:49.050 --> 00:00:49.883
They've said,

00:00:49.883 --> 00:00:51.360
"All right, let's think
about a given element."

00:00:51.360 --> 00:00:54.793
So say lithium, we know it's
average atomic mass is 6.94.

00:00:55.693 --> 00:01:00.693
6.94 unified atomic mass units per atom,

00:01:02.520 --> 00:01:05.160
atom of lithium.

00:01:05.160 --> 00:01:09.360
What if there were a certain
number of atoms of lithium

00:01:09.360 --> 00:01:12.360
such that if I have that number,

00:01:12.360 --> 00:01:17.360
so times certain number of atoms,

00:01:19.200 --> 00:01:24.200
then I will actually end up
with 6.94 grams of lithium

00:01:28.710 --> 00:01:31.200
and this number of atoms is

00:01:31.200 --> 00:01:34.833
6.02214076 times 10 to the 23rd power.

00:01:40.830 --> 00:01:44.910
So if you have a sample with
this number of lithium atoms,

00:01:44.910 --> 00:01:49.170
that sample is going to
have a mass of 6.94 grams,

00:01:49.170 --> 00:01:51.150
whatever its average atomic masses

00:01:51.150 --> 00:01:53.460
in terms of unified atomic mass units,

00:01:53.460 --> 00:01:56.880
if you have that number of the atom,

00:01:56.880 --> 00:02:01.880
you will have a mass of that
same number in terms of grams.

00:02:02.430 --> 00:02:05.820
Now, you might be saying, "Is
there a name for this number?"

00:02:05.820 --> 00:02:07.680
And there is indeed a name

00:02:07.680 --> 00:02:10.080
and it is called Avogadro's Number,

00:02:10.080 --> 00:02:14.460
named in honor of the early
19th century Italian chemist,

00:02:14.460 --> 00:02:16.423
Amedeo Avogadro and in most contexts,

00:02:16.423 --> 00:02:20.790
because you're not
normally dealing with data

00:02:20.790 --> 00:02:23.220
with this many significant digits,

00:02:23.220 --> 00:02:27.390
we will usually approximate it as 6.022

00:02:27.390 --> 00:02:30.840
times 10 to the 23rd power.

00:02:30.840 --> 00:02:33.990
Now, there's another word
that it's very useful

00:02:33.990 --> 00:02:36.420
to familiarize yourself with in chemistry

00:02:36.420 --> 00:02:40.350
and that's the idea of a mole.

00:02:40.350 --> 00:02:42.900
Now, what is a mole?

00:02:42.900 --> 00:02:44.790
It is not a little mark on your cheek,

00:02:44.790 --> 00:02:46.320
it is not a burrowing animal,

00:02:46.320 --> 00:02:48.210
actually, it is both of those things.

00:02:48.210 --> 00:02:49.950
But in a chemistry context,

00:02:49.950 --> 00:02:54.690
a mole is just saying you
have this much of something.

00:02:54.690 --> 00:02:57.300
The word mole was first
used by the German chemist,

00:02:57.300 --> 00:03:00.870
Wilhelm Oswald, at the
end of the 19th century

00:03:00.870 --> 00:03:02.160
and he came up with the word

00:03:02.160 --> 00:03:05.010
because of its relation to molecule.

00:03:05.010 --> 00:03:06.780
Now, what does that mean?

00:03:06.780 --> 00:03:09.270
Well, think about the word dozen.

00:03:09.270 --> 00:03:14.270
If I say I've got a dozen of
eggs, how many eggs do I have?

00:03:14.670 --> 00:03:18.570
Well, if I have a dozen of
eggs, that means I have 12 eggs.

00:03:18.570 --> 00:03:22.230
So if I say I have a
mole of lithium atoms,

00:03:22.230 --> 00:03:24.780
how many lithium atoms do I have?

00:03:24.780 --> 00:03:29.670
That means that I have 6.02214076

00:03:29.670 --> 00:03:33.240
times 10 to the 23rd lithium atoms.

00:03:33.240 --> 00:03:34.620
Exact same idea.

00:03:34.620 --> 00:03:37.770
It's just that Avagadro's
Number is a much hairier

00:03:37.770 --> 00:03:40.083
of a number than a dozen.


Worked example: calculating ion charge

WEBVTT
Kind: captions
Language: en

00:00:00.360 --> 00:00:02.460
- [Instructor] So we're
asked, what is the charge

00:00:02.460 --> 00:00:06.630
of a calcium ion with 18 electrons?

00:00:06.630 --> 00:00:08.220
So pause this video and see if you

00:00:08.220 --> 00:00:09.720
can work that on your own.

00:00:09.720 --> 00:00:12.540
And I will give you a little bit of a tip.

00:00:12.540 --> 00:00:16.620
A periodic table of elements
might be useful to see

00:00:16.620 --> 00:00:20.640
where calcium sits on that
periodic table of elements.

00:00:20.640 --> 00:00:22.170
So why don't you pause this video

00:00:22.170 --> 00:00:23.398
and see if you can
figure out the charge of

00:00:23.398 --> 00:00:25.833
that calcium ion.

00:00:27.600 --> 00:00:31.197
All right, so what defines
the element is actually

00:00:31.197 --> 00:00:34.110
how many protons it has,

00:00:34.110 --> 00:00:36.180
and that's what we have right over here.

00:00:36.180 --> 00:00:40.290
It's a atomic number is 20,
that's how many protons it has.

00:00:40.290 --> 00:00:44.160
So we could say number of
protons which provide positive

00:00:44.160 --> 00:00:46.500
charge is 20.

00:00:46.500 --> 00:00:49.770
And then we know the
number of electrons is 18.

00:00:49.770 --> 00:00:51.330
That's negative charge.

00:00:51.330 --> 00:00:52.163
So I'll just write it here.

00:00:52.163 --> 00:00:55.874
Number electrons, I'll
abbreviate it right over there

00:00:55.874 --> 00:00:57.176
or I'll shorten it.

00:00:57.176 --> 00:00:59.640
That is 18.

00:00:59.640 --> 00:01:01.140
And this has negative charge.

00:01:01.140 --> 00:01:04.170
So if you wanna know the net
charge, you take the number

00:01:04.170 --> 00:01:05.970
of protons, the positive charge

00:01:05.970 --> 00:01:08.190
and subtract out the number of electrons.

00:01:08.190 --> 00:01:12.210
And so that leaves you
with positive two charge,

00:01:12.210 --> 00:01:15.450
20 minus 18 is positive two,

00:01:15.450 --> 00:01:18.090
and we will denote that with a two plus.

00:01:18.090 --> 00:01:20.234
So some people might
write this as calcium 2+

00:01:20.234 --> 00:01:22.286
just like that.

00:01:22.286 --> 00:01:25.170
To show that it is a calcium ion,

00:01:25.170 --> 00:01:26.460
it's likely a situation maybe

00:01:26.460 --> 00:01:30.540
where the calcium
originally had 20 electrons

00:01:30.540 --> 00:01:31.860
and 20 protons.

00:01:31.860 --> 00:01:33.089
So then it would not be an ion,

00:01:33.089 --> 00:01:36.030
it would just be a neutral atom.

00:01:36.030 --> 00:01:38.836
But maybe it lost those, it
lost two of those electrons

00:01:38.836 --> 00:01:43.800
and so then it got a positive
two or a two plus charge.

00:01:43.800 --> 00:01:46.830
Let's do another example over here.

00:01:46.830 --> 00:01:49.809
So if I were to ask you
what is the charge of an ion

00:01:49.809 --> 00:01:52.552
that has seven protons, eight neutrons,

00:01:52.552 --> 00:01:56.370
and 10 electrons, pause this video

00:01:56.370 --> 00:01:58.120
and think about what that would be.

00:01:59.040 --> 00:02:01.740
Well, we can confirm that
that indeed would be an ion

00:02:01.740 --> 00:02:02.663
because it has a different number

00:02:02.663 --> 00:02:05.970
of protons than it does electrons.

00:02:05.970 --> 00:02:07.890
And if you wanna figure out the charge,

00:02:07.890 --> 00:02:10.377
you just take the number
of protons, seven,

00:02:10.377 --> 00:02:12.300
which are the positive charges,

00:02:12.300 --> 00:02:14.040
and you subtract out the negative charges.

00:02:14.040 --> 00:02:15.090
That's why you're subtracting,

00:02:15.090 --> 00:02:16.440
you subtract out the electrons.

00:02:16.440 --> 00:02:20.130
So seven minus 10, that would
be equal to negative three.

00:02:20.130 --> 00:02:23.040
And so I would say you'd often denote that

00:02:23.040 --> 00:02:25.530
as saying a three minus charge.

00:02:25.530 --> 00:02:28.590
And if you wanted to write
down what ion that is,

00:02:28.590 --> 00:02:30.472
once it's gonna go back to the
periodic table of elements,

00:02:30.472 --> 00:02:34.020
we can see that if you have seven protons,

00:02:34.020 --> 00:02:37.273
by definition you are
talking about nitrogen.

00:02:37.273 --> 00:02:39.627
So that would be a nitrogen ion

00:02:39.627 --> 00:02:42.000
that you would denote like that.

00:02:42.000 --> 00:02:45.633
It has a negative three
or a three minus charge.


Worked example: using the mass number equation

WEBVTT
Kind: captions
Language: en

00:00:01.290 --> 00:00:02.580
- [Instructor] Hi, everyone.

00:00:02.580 --> 00:00:04.650
In this video we're going to practice

00:00:04.650 --> 00:00:07.110
using the mass number equation.

00:00:07.110 --> 00:00:09.090
This equation represents the fact

00:00:09.090 --> 00:00:11.820
that the mass number of an atom is equal

00:00:11.820 --> 00:00:15.963
to its number of protons
plus its number of neutrons.

00:00:17.160 --> 00:00:19.110
Let's use the mass number equation

00:00:19.110 --> 00:00:21.750
to answer the following question.

00:00:21.750 --> 00:00:24.990
How many neutrons are
in an isotope of sodium

00:00:24.990 --> 00:00:26.583
with the following notation?

00:00:28.650 --> 00:00:30.690
To answer this question, we'll first need

00:00:30.690 --> 00:00:33.780
to rearrange our mass
number equation to solve

00:00:33.780 --> 00:00:35.850
for the number of neutrons.

00:00:35.850 --> 00:00:38.913
Pause the video and take a
moment to try this for yourself.

00:00:40.530 --> 00:00:43.410
The rearranged equation is as follows.

00:00:43.410 --> 00:00:46.680
The number of neutrons
equals the mass number

00:00:46.680 --> 00:00:49.560
minus the number of protons.

00:00:49.560 --> 00:00:51.390
Based on this notation, we know

00:00:51.390 --> 00:00:53.820
that this sodium isotope has a mass number

00:00:53.820 --> 00:00:58.500
of 23 and an atomic number of 11.

00:00:58.500 --> 00:01:01.620
If we subtract the atomic number 11

00:01:01.620 --> 00:01:05.790
from the mass number
23, we're left with 12,

00:01:05.790 --> 00:01:09.063
which is the number of neutrons
in this sodium isotope.

00:01:11.010 --> 00:01:16.010
Okay, more practice, this time
with an isotope of platinum.

00:01:16.290 --> 00:01:18.960
How many neutrons does this isotope have

00:01:18.960 --> 00:01:23.523
based on the following notation, Pt-195?

00:01:24.480 --> 00:01:28.020
Again, we'll need to use the
rearranged mass number equation

00:01:28.020 --> 00:01:30.063
to solve for the number of neutrons.

00:01:31.380 --> 00:01:34.230
This particular notation
provides the chemical symbol

00:01:34.230 --> 00:01:37.260
of platinum and its mass number.

00:01:37.260 --> 00:01:39.660
We can look up platinum
on the periodic table

00:01:39.660 --> 00:01:43.140
to find its atomic number, which is 78,

00:01:43.140 --> 00:01:46.740
meaning that every platinum
atom has 78 protons.

00:01:46.740 --> 00:01:49.740
We can subtract the atomic number 78

00:01:49.740 --> 00:01:54.740
from the mass number 195 to get 117,

00:01:54.750 --> 00:01:59.750
so this isotope of
platinum has 117 neutrons.


Isotopes

WEBVTT
Kind: captions
Language: en

00:00:00.360 --> 00:00:02.130
- [Instructor] Every element is defined

00:00:02.130 --> 00:00:04.590
by the number of protons in its atoms,

00:00:04.590 --> 00:00:06.990
which is called its atomic number.

00:00:06.990 --> 00:00:11.670
So for example, every atom
of potassium has 19 protons

00:00:11.670 --> 00:00:15.570
and every atom of cobalt has 27 protons.

00:00:15.570 --> 00:00:17.970
But what about neutrons?

00:00:17.970 --> 00:00:20.760
Well, an element doesn't
always have the same number

00:00:20.760 --> 00:00:23.130
of neutrons in its atoms.

00:00:23.130 --> 00:00:26.550
Atoms of the same element with
different numbers of neutrons

00:00:26.550 --> 00:00:28.173
are called isotopes.

00:00:29.430 --> 00:00:31.230
Because isotopes of an element

00:00:31.230 --> 00:00:33.300
have different numbers of neutrons,

00:00:33.300 --> 00:00:36.510
those isotopes also have different masses.

00:00:36.510 --> 00:00:38.850
Remember, most of the mass of an atom

00:00:38.850 --> 00:00:42.180
comes from the protons and
neutrons in its nucleus.

00:00:42.180 --> 00:00:44.940
In fact, the sum of the number of protons

00:00:44.940 --> 00:00:49.320
and neutrons in an atom
is called its mass number.

00:00:49.320 --> 00:00:53.070
We can write this in the form
of an equation as follows,

00:00:53.070 --> 00:00:56.070
mass number equals the number of protons,

00:00:56.070 --> 00:00:58.383
plus the number of neutrons.

00:00:59.520 --> 00:01:02.550
Next, let's dive into isotope notation,

00:01:02.550 --> 00:01:05.640
or how we represent isotopes in writing.

00:01:05.640 --> 00:01:07.440
When describing different isotopes,

00:01:07.440 --> 00:01:09.270
you'll often see this notation

00:01:09.270 --> 00:01:11.700
where X is the chemical symbol,

00:01:11.700 --> 00:01:14.700
which is an abbreviation
of the element's name,

00:01:14.700 --> 00:01:19.020
A is the mass number, the
number of protons plus neutrons,

00:01:19.020 --> 00:01:22.503
and Z is the atomic number,
the number of protons.

00:01:24.210 --> 00:01:26.190
Let's practice writing out the notation

00:01:26.190 --> 00:01:27.930
for different isotopes.

00:01:27.930 --> 00:01:29.100
We'll start with carbon,

00:01:29.100 --> 00:01:31.860
which has an atomic number of 6.

00:01:31.860 --> 00:01:33.960
In nature, carbon is mainly composed

00:01:33.960 --> 00:01:35.940
of two different isotopes.

00:01:35.940 --> 00:01:38.070
One of these isotopes has 6 neutrons

00:01:38.070 --> 00:01:41.100
and the other isotope has 7 neutrons.

00:01:41.100 --> 00:01:42.240
Let's start with the isotope

00:01:42.240 --> 00:01:45.600
that has 6 protons and 6 neutrons.

00:01:45.600 --> 00:01:46.590
With that information,

00:01:46.590 --> 00:01:49.530
we know that the mass number must be 12,

00:01:49.530 --> 00:01:52.890
which is the sum of the
protons and neutrons.

00:01:52.890 --> 00:01:55.830
So the notation for this isotope of carbon

00:01:55.830 --> 00:01:57.153
would look like this.

00:01:58.230 --> 00:02:00.510
We have the chemical symbol C

00:02:00.510 --> 00:02:03.720
with the mass number 12
written at its top-left,

00:02:03.720 --> 00:02:07.743
and the atomic number 6
written at its bottom-left.

00:02:08.670 --> 00:02:13.470
But for the isotope with
6 protons and 7 neutrons,

00:02:13.470 --> 00:02:17.820
the mass number would be 6 plus 7, or 13.

00:02:17.820 --> 00:02:21.843
So the notation for the carbon
isotope would be as follows.

00:02:22.980 --> 00:02:25.830
Here, we have the chemical symbol C

00:02:25.830 --> 00:02:29.280
with the mass number 13
written at its top-left,

00:02:29.280 --> 00:02:32.523
and the atomic number 6
written at its bottom-left.

00:02:33.660 --> 00:02:36.570
Notice that the chemical
symbol and atomic number

00:02:36.570 --> 00:02:40.230
share the same information,
the identity of the element,

00:02:40.230 --> 00:02:43.140
and are the same for both isotopes,

00:02:43.140 --> 00:02:46.500
but the mass number is
different for each isotope

00:02:46.500 --> 00:02:49.650
depending on the number of neutrons.

00:02:49.650 --> 00:02:52.230
Another notation that is used for isotopes

00:02:52.230 --> 00:02:55.140
is the chemical symbol
or the element's name,

00:02:55.140 --> 00:02:58.170
symbolized by X, followed by a hyphen,

00:02:58.170 --> 00:03:02.390
and the mass number,
symbolized by A, so X-A.

00:03:04.740 --> 00:03:07.680
Let's return to our
carbon isotopes example.

00:03:07.680 --> 00:03:11.910
For the carbon isotope that
has 6 protons and 6 neutrons,

00:03:11.910 --> 00:03:16.800
we write that as C-12 or carbon-12.

00:03:16.800 --> 00:03:20.940
For the carbon isotope with
6 protons and 7 neutrons,

00:03:20.940 --> 00:03:24.993
we write that as C-13 or carbon-13.

00:03:26.160 --> 00:03:29.460
Let's wrap up this video
with a quick recap.

00:03:29.460 --> 00:03:31.320
We know that elements are defined

00:03:31.320 --> 00:03:34.020
by the number of protons in their atoms,

00:03:34.020 --> 00:03:36.240
but atoms of the same element

00:03:36.240 --> 00:03:38.820
can have different numbers of neutrons.

00:03:38.820 --> 00:03:41.070
These are called isotopes.

00:03:41.070 --> 00:03:43.890
Because isotopes have
different numbers of neutrons,

00:03:43.890 --> 00:03:46.500
they also have different mass numbers,

00:03:46.500 --> 00:03:49.080
which are the sum of
the protons and neutrons

00:03:49.080 --> 00:03:50.793
in each isotope's atom.

00:03:51.900 --> 00:03:55.530
An atom's mass number can be
described by the equation,

00:03:55.530 --> 00:03:59.520
mass number equals the number of protons,

00:03:59.520 --> 00:04:02.220
plus the number of neutrons.

00:04:02.220 --> 00:04:04.980
And lastly, we can describe isotopes

00:04:04.980 --> 00:04:06.900
using a couple of different notations,

00:04:06.900 --> 00:04:08.223
which are shown below.


Elements and atomic number

WEBVTT
Kind: captions
Language: en

00:00:00.660 --> 00:00:02.790
- [Instructor] We know that
everything in the universe

00:00:02.790 --> 00:00:04.860
is composed of atoms,

00:00:04.860 --> 00:00:07.443
but not all atoms are the same.

00:00:08.340 --> 00:00:11.880
There are many different types
of atoms called elements,

00:00:11.880 --> 00:00:16.050
each with a unique set of
physical and chemical properties.

00:00:16.050 --> 00:00:18.900
Many elements are
probably familiar to you.

00:00:18.900 --> 00:00:22.110
Oxygen and carbon, for
example, are elements,

00:00:22.110 --> 00:00:23.643
and so is gold.

00:00:25.170 --> 00:00:27.150
Others may be less familiar

00:00:27.150 --> 00:00:30.243
such as bismuth, xenon, and osmium.

00:00:32.340 --> 00:00:34.290
A particular element is identified

00:00:34.290 --> 00:00:36.750
by the number of protons in its atoms.

00:00:36.750 --> 00:00:40.080
And the number of protons
in the nucleus of an atom

00:00:40.080 --> 00:00:43.983
is its atomic number,
represented by the symbol Z.

00:00:45.000 --> 00:00:49.050
For example, helium has
an atomic number of two.

00:00:49.050 --> 00:00:53.520
That means that every
helium atom has two protons.

00:00:53.520 --> 00:00:56.940
And here's another example, iron,

00:00:56.940 --> 00:00:59.250
its atomic number is 26,

00:00:59.250 --> 00:01:03.003
so every iron atom has 26 protons.

00:01:03.930 --> 00:01:06.480
An element's atomic
number can also tell us

00:01:06.480 --> 00:01:10.200
the number of electrons in a
neutral atom of an element.

00:01:10.200 --> 00:01:14.430
Remember, equal and opposite
charges cancel each other out

00:01:14.430 --> 00:01:16.200
so to be neutral,

00:01:16.200 --> 00:01:19.320
an atom must have an
equal number of protons,

00:01:19.320 --> 00:01:21.210
which have a charge of 1+,

00:01:21.210 --> 00:01:23.577
and electrons, which have a charge of 1-.

00:01:24.570 --> 00:01:27.900
This means that our helium
atom must have two electrons

00:01:27.900 --> 00:01:31.683
and our iron atom must have 26 electrons.

00:01:33.210 --> 00:01:34.710
All of the known elements

00:01:34.710 --> 00:01:37.770
are organized according
to their atomic numbers

00:01:37.770 --> 00:01:39.660
in the periodic table.

00:01:39.660 --> 00:01:42.240
The periodic table lists the elements

00:01:42.240 --> 00:01:44.460
in order of increasing atomic number

00:01:44.460 --> 00:01:48.630
as you go from left to right
and from top to bottom.

00:01:48.630 --> 00:01:51.570
The elements are further
organized into columns

00:01:51.570 --> 00:01:53.340
based on their properties.

00:01:53.340 --> 00:01:54.960
Elements in the same column

00:01:54.960 --> 00:01:58.263
tend to have similar physical
and chemical properties.

00:01:59.370 --> 00:02:03.150
Every element is represented
by a chemical symbol,

00:02:03.150 --> 00:02:05.790
a unique one or two letter abbreviation

00:02:05.790 --> 00:02:08.310
that appears below the
element's atomic number

00:02:08.310 --> 00:02:10.200
on the periodic table.

00:02:10.200 --> 00:02:11.280
Many chemical symbols

00:02:11.280 --> 00:02:14.100
are based on the English
name for an element.

00:02:14.100 --> 00:02:17.130
For example, the symbol for hydrogen is H,

00:02:17.130 --> 00:02:19.413
and the symbol for aluminum is Al.

00:02:20.250 --> 00:02:21.930
But some chemical symbols

00:02:21.930 --> 00:02:24.660
are based on the Latin
name for the element.

00:02:24.660 --> 00:02:28.050
For example, the symbol for lead is Pb,

00:02:28.050 --> 00:02:32.100
which actually comes from
its Latin name plumbum.

00:02:32.100 --> 00:02:34.200
Notice that whenever the chemical symbol

00:02:34.200 --> 00:02:36.330
for an element has two letters,

00:02:36.330 --> 00:02:38.793
the second letter is written in lowercase.

00:02:40.140 --> 00:02:42.360
All of this information is contained

00:02:42.360 --> 00:02:45.930
inside of each element's
box on the periodic table.

00:02:45.930 --> 00:02:49.620
For example, here's the box
for the element nitrogen.

00:02:49.620 --> 00:02:50.850
At the top of the box

00:02:50.850 --> 00:02:54.480
is nitrogen's atomic
number, which is seven.

00:02:54.480 --> 00:02:56.010
Remember that this is equal

00:02:56.010 --> 00:02:59.520
to the number of protons
in each atom of nitrogen

00:02:59.520 --> 00:03:02.460
as well as the number of electrons.

00:03:02.460 --> 00:03:05.940
Below that is nitrogen's
chemical symbol, N,

00:03:05.940 --> 00:03:07.920
followed by its name.

00:03:07.920 --> 00:03:10.020
Often, you'll also see another number

00:03:10.020 --> 00:03:12.360
listed at the bottom of an elements box,

00:03:12.360 --> 00:03:15.120
which has to do with atomic mass.

00:03:15.120 --> 00:03:18.600
We'll cover details about
this and another video.

00:03:18.600 --> 00:03:20.070
What's neat about having

00:03:20.070 --> 00:03:22.230
all of this information in one place

00:03:22.230 --> 00:03:25.740
is that if we know one
detail about an element,

00:03:25.740 --> 00:03:29.700
either it's atomic number,
chemical symbol, or a name,

00:03:29.700 --> 00:03:31.770
we can often use the periodic table

00:03:31.770 --> 00:03:34.230
to find out the other details.

00:03:34.230 --> 00:03:36.720
Let's take a look at a few examples.

00:03:36.720 --> 00:03:39.660
Say we have the element phosphorus,

00:03:39.660 --> 00:03:42.873
what is its atomic number
and chemical symbol?

00:03:44.070 --> 00:03:45.960
Looking through the periodic table,

00:03:45.960 --> 00:03:47.460
we can find phosphorus

00:03:47.460 --> 00:03:50.490
and see that its atomic number is 15

00:03:50.490 --> 00:03:52.773
and its chemical symbol is P.

00:03:53.640 --> 00:03:55.650
Let's do another example.

00:03:55.650 --> 00:03:59.160
Say we know the chemical symbol Hg,

00:03:59.160 --> 00:04:00.780
what is this element's name

00:04:00.780 --> 00:04:03.243
and how many protons does it have?

00:04:04.320 --> 00:04:07.680
Here is the symbol Hg
on the periodic table.

00:04:07.680 --> 00:04:09.120
Its name is mercury,

00:04:09.120 --> 00:04:11.040
and its atomic number is 80

00:04:11.040 --> 00:04:13.593
so it has 80 protons.

00:04:14.790 --> 00:04:16.230
Let's reveal.

00:04:16.230 --> 00:04:17.670
The universe is made up

00:04:17.670 --> 00:04:20.430
of different types of
atoms called elements,

00:04:20.430 --> 00:04:23.490
and these elements are
organized by atomic number

00:04:23.490 --> 00:04:25.410
in the periodic table.

00:04:25.410 --> 00:04:29.250
So, the next time that you
stare up at the starry sky,

00:04:29.250 --> 00:04:33.153
you know that everything out
there is made up of elements.


Protons, neutrons, and electrons in atoms

WEBVTT
Kind: captions
Language: en

00:00:00.495 --> 00:00:03.960
- [Instructor] Everything in
our world is made up of atoms.

00:00:03.960 --> 00:00:05.880
Yep, everything.

00:00:05.880 --> 00:00:08.760
From the air we breathe
to the water we drink,

00:00:08.760 --> 00:00:11.580
even the materials inside our cellphones.

00:00:11.580 --> 00:00:13.800
But what are atoms exactly?

00:00:13.800 --> 00:00:15.870
What's inside of these atoms?

00:00:15.870 --> 00:00:18.123
What makes an atom an atom?

00:00:19.050 --> 00:00:22.500
Atoms are tiny particles that
are basic units of matter,

00:00:22.500 --> 00:00:24.180
like building blocks.

00:00:24.180 --> 00:00:26.280
But atoms themselves are made up

00:00:26.280 --> 00:00:29.490
of even smaller subatomic particles,

00:00:29.490 --> 00:00:33.063
called protons, neutrons, and electrons.

00:00:33.930 --> 00:00:35.728
Let's take a look at
the simplified diagram

00:00:35.728 --> 00:00:38.430
to learn more about
these subatomic particles

00:00:38.430 --> 00:00:40.800
and the structure of an atom.

00:00:40.800 --> 00:00:43.710
In the center of an atom,
we have the nucleus,

00:00:43.710 --> 00:00:47.520
which is composed of protons and neutrons.

00:00:47.520 --> 00:00:50.880
Outside the nucleus, we
have the electron cloud.

00:00:50.880 --> 00:00:54.475
This is where electrons are
most likely to be found.

00:00:54.475 --> 00:00:58.110
I've drawn the nucleus much
larger than it really is,

00:00:58.110 --> 00:01:00.270
but an atom's electron cloud can be

00:01:00.270 --> 00:01:03.900
100,000 times larger than its nucleus.

00:01:03.900 --> 00:01:06.210
So the electron cloud actually makes up

00:01:06.210 --> 00:01:08.043
most of the atom's volume.

00:01:08.970 --> 00:01:11.640
Protons, neutrons, and electrons differ

00:01:11.640 --> 00:01:14.068
in terms of their charge and mass.

00:01:14.068 --> 00:01:17.130
Let's take a look at charge first.

00:01:17.130 --> 00:01:20.400
Protons have a positive
charge of one plus,

00:01:20.400 --> 00:01:24.390
and electrons have a
negative charge of one minus.

00:01:24.390 --> 00:01:27.030
These charges are equal and opposite,

00:01:27.030 --> 00:01:30.900
so when protons and electrons
are paired in atoms,

00:01:30.900 --> 00:01:33.030
their charges cancel.

00:01:33.030 --> 00:01:36.483
Neutrons have no charge,
which means they are neutral.

00:01:37.590 --> 00:01:39.180
What about mass?

00:01:39.180 --> 00:01:41.550
The unit we use to express the masses

00:01:41.550 --> 00:01:45.600
of subatomic particles is
the unified atomic mass unit,

00:01:45.600 --> 00:01:47.163
abbreviated as U.

00:01:48.120 --> 00:01:52.620
Protons and neutrons have
a similar mass about one U.

00:01:52.620 --> 00:01:54.840
In comparison, electrons have a mass

00:01:54.840 --> 00:01:58.710
of about 0.0005 U,

00:01:58.710 --> 00:02:01.350
which makes them roughly
2,000 times smaller

00:02:01.350 --> 00:02:04.410
than either a proton or a neutron.

00:02:04.410 --> 00:02:06.372
This means that nearly all the mass

00:02:06.372 --> 00:02:08.692
of an atom resides in the nucleus,

00:02:08.692 --> 00:02:10.983
and not in the electron cloud.

00:02:12.330 --> 00:02:15.390
Atoms make up everything in our world,

00:02:15.390 --> 00:02:18.390
even though the air we
breathe, the water we drink,

00:02:18.390 --> 00:02:20.190
and the cellphones we use all look

00:02:20.190 --> 00:02:22.290
really different from one another,

00:02:22.290 --> 00:02:25.290
the atoms that make up these
things are all composed

00:02:25.290 --> 00:02:27.600
of the same subatomic particles;

00:02:27.600 --> 00:02:30.453
protons, neutrons, and electrons.


Irregular plural nouns

WEBVTT
Kind: captions
Language: en

00:00:00.270 --> 00:00:01.380
- [David] Hello, grammarians.

00:00:01.380 --> 00:00:04.860
Today, we're going to be talking
about the irregular plural.

00:00:04.860 --> 00:00:08.550
Previously, I had said that
if you take any English word,

00:00:08.550 --> 00:00:10.503
any noun, say the word dog,

00:00:11.940 --> 00:00:14.730
and you tack an S onto
the end of it like so,

00:00:14.730 --> 00:00:16.320
boop, you get the word dogs.

00:00:16.320 --> 00:00:20.700
And that's how you form
the plural in all cases.

00:00:20.700 --> 00:00:23.160
I was lying, sorry.

00:00:23.160 --> 00:00:25.830
It turns out that English is
a little bit more complicated

00:00:25.830 --> 00:00:26.663
than that.

00:00:26.663 --> 00:00:28.530
While adding an S to things

00:00:28.530 --> 00:00:31.140
is the way you usually make things plural,

00:00:31.140 --> 00:00:32.820
sometimes there are other changes.

00:00:32.820 --> 00:00:34.890
And sometimes you don't even pluralize

00:00:34.890 --> 00:00:36.120
using an S at the end,

00:00:36.120 --> 00:00:37.290
but we're not gonna talk about that now.

00:00:37.290 --> 00:00:38.730
That's for another time.

00:00:38.730 --> 00:00:40.830
What I wanna talk about today

00:00:40.830 --> 00:00:43.980
is the most basic kind
of irregular plural.

00:00:43.980 --> 00:00:45.990
So we have the difference in English

00:00:45.990 --> 00:00:50.973
between regular and irregular plurals.

00:00:56.430 --> 00:00:57.263
And remember,

00:00:57.263 --> 00:01:01.380
a plural is when there's
more than one of something.

00:01:01.380 --> 00:01:06.087
It comes from the Latin
plus, which means "more."

00:01:07.020 --> 00:01:08.880
As opposed to the singular

00:01:08.880 --> 00:01:11.373
when there is just one of something.

00:01:16.440 --> 00:01:20.730
You know, one dog, two dogs.

00:01:20.730 --> 00:01:22.680
So there's a handful of words in English,

00:01:22.680 --> 00:01:24.210
and it really is a handful,

00:01:24.210 --> 00:01:26.793
that don't pluralize regularly.

00:01:27.840 --> 00:01:30.723
Words like "leaf" and "loaf"

00:01:32.070 --> 00:01:35.250
and "calf," that's a baby cow.

00:01:35.250 --> 00:01:36.810
If you try to pluralize these

00:01:36.810 --> 00:01:38.220
as though they were regular plurals,

00:01:38.220 --> 00:01:42.000
you're gonna return something
that is not correct,

00:01:42.000 --> 00:01:43.680
or at least is not conventional

00:01:43.680 --> 00:01:46.890
within modern standard
American English, right?

00:01:46.890 --> 00:01:48.810
So "leafs," for example,

00:01:48.810 --> 00:01:51.030
unless you're talking about
the Toronto hockey team,

00:01:51.030 --> 00:01:52.770
is not correct.

00:01:52.770 --> 00:01:54.630
In fact, the proper term,

00:01:54.630 --> 00:01:57.150
boop, boop, boop, boop, boop, boop,

00:01:57.150 --> 00:02:00.000
is in fact "leaves."

00:02:00.000 --> 00:02:03.840
It is not "loafs," but "loaves."

00:02:03.840 --> 00:02:05.460
Tasty loaves of bread.

00:02:05.460 --> 00:02:09.690
It is not "calfs," but "calves."

00:02:09.690 --> 00:02:12.300
So there are several different
kinds of irregular plurals.

00:02:12.300 --> 00:02:14.430
That's why this video is called Part I,

00:02:14.430 --> 00:02:17.250
but I'm only going to cover one
such irregular plural today,

00:02:17.250 --> 00:02:22.120
and that is the change from
singular f to plural ve

00:02:22.980 --> 00:02:25.560
An important caveat, an
important exception here

00:02:25.560 --> 00:02:26.760
is double-f.

00:02:26.760 --> 00:02:29.550
Words like "cliff" or
"sheriff" or "sniff,"

00:02:29.550 --> 00:02:33.240
do not change to ve or ves in the plural.

00:02:33.240 --> 00:02:36.690
They become "cliffs,"
"sheriffs," "sniffs."

00:02:36.690 --> 00:02:38.370
There are exceptions to that too, right?

00:02:38.370 --> 00:02:40.020
Like "staff" to "staves."

00:02:40.020 --> 00:02:43.680
But for the most part,
double-f doesn't change to ve.

00:02:43.680 --> 00:02:45.120
Single f mostly does, right?

00:02:45.120 --> 00:02:46.380
That's the general rule.

00:02:46.380 --> 00:02:47.850
Singular word, ends in f,

00:02:47.850 --> 00:02:49.687
the plur will be ves.

00:02:49.687 --> 00:02:53.400
"Leaf" to "leaves," "loaf" to
"loaves," "calf" to "calves."

00:02:53.400 --> 00:02:56.850
Generally, for the most part.

00:02:56.850 --> 00:02:59.070
English, ah, so silly.

00:02:59.070 --> 00:03:02.670
Who's driving this
thing? We love it though.

00:03:02.670 --> 00:03:05.073
You can learn anything. David out.


Khanmigo: Co-create a Rubric Activity

WEBVTT
Kind: captions
Language: en

00:00:00.750 --> 00:00:02.010
- [Instructor] This is Khanmigo,

00:00:02.010 --> 00:00:05.730
an AI-powered guide designed
to help all students learn.

00:00:05.730 --> 00:00:07.860
Khanmigo is not just for students,

00:00:07.860 --> 00:00:09.630
teachers can use Khanmigo too,

00:00:09.630 --> 00:00:11.490
by toggling from the Student mode

00:00:11.490 --> 00:00:13.410
to Teacher mode in any course,

00:00:13.410 --> 00:00:15.570
and teachers can always access Khanmigo

00:00:15.570 --> 00:00:17.910
by selecting the AI Activities button

00:00:17.910 --> 00:00:20.160
located at the top of
the teacher dashboard.

00:00:20.160 --> 00:00:23.130
Khanmigo has many exciting
features that support teachers,

00:00:23.130 --> 00:00:26.790
and this video will showcase
ways teachers can use Khanmigo

00:00:26.790 --> 00:00:28.890
to create core-specific rubrics

00:00:28.890 --> 00:00:31.680
to enhance learning
experiences for their students.

00:00:31.680 --> 00:00:34.380
Once I select the
Co-create a Rubric feature,

00:00:34.380 --> 00:00:36.780
Khanmigo requests the
objective for the lesson,

00:00:36.780 --> 00:00:39.180
and wants to know what
I'm planning to grade.

00:00:39.180 --> 00:00:42.510
If I know the standard, I
can include that as well.

00:00:42.510 --> 00:00:45.450
My students are going to
be writing a research paper

00:00:45.450 --> 00:00:48.900
for a science lesson
that we just completed.

00:00:48.900 --> 00:00:52.830
The standard is this,

00:00:52.830 --> 00:00:56.490
I love that Khanmigo knows
exactly what I'm talking about.

00:00:56.490 --> 00:00:58.740
Khanmigo will then ask
me a series of questions

00:00:58.740 --> 00:01:01.920
throughout this process, so
that we are truly collaborating

00:01:01.920 --> 00:01:04.590
to co-create the perfect
rubric that I want.

00:01:04.590 --> 00:01:05.550
Throughout the process,

00:01:05.550 --> 00:01:08.010
Khanmigo's always going to want my input

00:01:08.010 --> 00:01:10.440
and ask me if I wanna make any changes.

00:01:10.440 --> 00:01:14.130
Could you simplify the
explanation a bit for my students?

00:01:14.130 --> 00:01:16.470
Ah, this is much better.

00:01:16.470 --> 00:01:18.510
Once I've answered all
of Khanmigo's questions,

00:01:18.510 --> 00:01:19.590
the magic begins,

00:01:19.590 --> 00:01:23.100
and Khanmigo creates a rubric
that is detailed and specific

00:01:23.100 --> 00:01:24.840
so my students will know exactly

00:01:24.840 --> 00:01:26.580
what they're being graded on.

00:01:26.580 --> 00:01:29.160
And if I have any EL students,

00:01:29.160 --> 00:01:31.920
I can always ask Khanmigo
to translate the rubric

00:01:31.920 --> 00:01:34.230
for my students or my parents.

00:01:34.230 --> 00:01:36.900
This is saving me so much time.

00:01:36.900 --> 00:01:38.300
Thank you so much, Khanmigo.


Khanmigo: Class Snapshot Activity

WEBVTT
Kind: captions
Language: en

00:00:00.000 --> 00:00:02.880
- [Narrator] This is
Khanmigo, an AI-powered guide

00:00:02.880 --> 00:00:05.340
designed to help all students learn.

00:00:05.340 --> 00:00:07.830
Khanmigo is not just for students though.

00:00:07.830 --> 00:00:09.570
Teachers can use Khanmigo too

00:00:09.570 --> 00:00:13.020
by toggling from Student
Mode to Teacher Mode.

00:00:13.020 --> 00:00:15.600
Once in Teacher Mode, Khanmigo transforms

00:00:15.600 --> 00:00:18.270
into the teaching assistant
you've always wanted.

00:00:18.270 --> 00:00:21.330
Khanmigo has many exciting
features that support teachers

00:00:21.330 --> 00:00:25.140
and this video will showcase
ways teachers can use Khanmigo

00:00:25.140 --> 00:00:27.330
to track their students' progress.

00:00:27.330 --> 00:00:30.033
This feature is called the Class Snapshot.

00:00:30.900 --> 00:00:34.140
Once the Class Snapshot
feature is selected,

00:00:34.140 --> 00:00:36.360
Khanmigo will ask you which course

00:00:36.360 --> 00:00:38.970
do you want to use the Class Snapshot for?

00:00:38.970 --> 00:00:41.280
I'm going to select Algebra 1.

00:00:41.280 --> 00:00:44.640
Once that button is selected,
Khanmigo springs into action

00:00:44.640 --> 00:00:47.460
and tells me how my
students have performed

00:00:47.460 --> 00:00:49.980
the last seven days in my course.

00:00:49.980 --> 00:00:52.830
Khanmigo will show me their learning time.

00:00:52.830 --> 00:00:54.840
Khanmigo will show me
how they're performing

00:00:54.840 --> 00:00:57.300
on their assignments,
how they're performing

00:00:57.300 --> 00:01:00.360
on their skills, and
how they are performing

00:01:00.360 --> 00:01:02.313
towards their mastery goals.

00:01:03.150 --> 00:01:06.030
Khanmigo also includes additional
prompts to help guide me

00:01:06.030 --> 00:01:09.630
into diving into my students'
data, such as which students

00:01:09.630 --> 00:01:12.810
should I celebrate for their
work on their assignments?

00:01:12.810 --> 00:01:15.360
Who needs a check-in about
their skills progress

00:01:15.360 --> 00:01:16.710
for the week?

00:01:16.710 --> 00:01:20.070
Give me a list of
students who are above 25%

00:01:20.070 --> 00:01:21.750
on their mastery goal.

00:01:21.750 --> 00:01:24.000
And I think this one may be my favorite,

00:01:24.000 --> 00:01:26.520
group my class by their recommendations.

00:01:26.520 --> 00:01:29.370
This feature really does
help me when I wanna do

00:01:29.370 --> 00:01:31.560
skill-based group instruction.

00:01:31.560 --> 00:01:33.660
When I select the who needs a check-in

00:01:33.660 --> 00:01:35.850
about their skills progress for the week,

00:01:35.850 --> 00:01:38.430
Khanmigo creates a list of students

00:01:38.430 --> 00:01:40.680
that they think I should check on

00:01:40.680 --> 00:01:42.510
who may need a nudge in the course

00:01:42.510 --> 00:01:46.200
because they haven't been
leveling up two skills per week.

00:01:46.200 --> 00:01:48.180
I'm able to see the list of students.

00:01:48.180 --> 00:01:51.360
And again, Khanmigo
gives me a helpful link

00:01:51.360 --> 00:01:54.660
that I could click on that
will give me direct access

00:01:54.660 --> 00:01:56.910
to the report that I need.

00:01:56.910 --> 00:01:59.010
After having my data
chats with my students

00:01:59.010 --> 00:02:01.650
who are struggling, I
can also use Khanmigo

00:02:01.650 --> 00:02:04.380
to help me draft an email
that I can send home

00:02:04.380 --> 00:02:08.130
to parents about their students' progress.

00:02:08.130 --> 00:02:13.130
Create a parent letter for
Paul about his progress.

00:02:21.630 --> 00:02:25.863
And then I just let Khanmigo
do Khanmigo's magic.

00:02:27.180 --> 00:02:30.390
This is wonderful. Thank
you so much, Khanmigo.

00:02:30.390 --> 00:02:34.500
Oops, I totally forgot.
Paul's mom speaks Spanish.

00:02:34.500 --> 00:02:39.500
Could you please
translate this to Spanish?

00:02:43.740 --> 00:02:47.730
Again, one click of the
button and my email is ready

00:02:47.730 --> 00:02:49.680
to go to Paul's mom.

00:02:49.680 --> 00:02:53.310
This is an amazing feature.
Thank you so much, Khanmigo.

00:02:53.310 --> 00:02:54.960
I appreciate all of your help.

00:02:54.960 --> 00:02:57.450
You have saved me so much time.

00:02:57.450 --> 00:03:00.030
Thanks so much for watching
and be on the lookout

00:03:00.030 --> 00:03:03.240
for more videos to come
on how to use Khanmigo

00:03:03.240 --> 00:03:05.043
to support your students.


Khanmigo: Teacher Activities Overview

WEBVTT
Kind: captions
Language: en

00:00:01.890 --> 00:00:04.380
- [Instructor] This is
Khanmigo, an AI-powered guide

00:00:04.380 --> 00:00:06.930
designed to help all students learn.

00:00:06.930 --> 00:00:09.030
Khanmigo is not just for students, though,

00:00:09.030 --> 00:00:11.070
teachers can use Khanmigo too.

00:00:11.070 --> 00:00:13.920
In fact, when teachers access Khanmigo,

00:00:13.920 --> 00:00:16.470
their device will transform
into the teaching assistant

00:00:16.470 --> 00:00:17.760
they've always wanted.

00:00:17.760 --> 00:00:19.560
Let's take a look.

00:00:19.560 --> 00:00:21.630
Upon entering Khanmigo's dashboard,

00:00:21.630 --> 00:00:23.490
you're able to see all
of the wonderful things

00:00:23.490 --> 00:00:25.560
that Khanmigo can do.

00:00:25.560 --> 00:00:27.780
Khanmigo can give you a class snapshot

00:00:27.780 --> 00:00:30.750
into your student's activity
the last seven days.

00:00:30.750 --> 00:00:33.150
It can summarize your
student's chat history

00:00:33.150 --> 00:00:35.670
so you can see what they've been up to.

00:00:35.670 --> 00:00:38.640
Need help with a upcoming lesson plan?

00:00:38.640 --> 00:00:40.563
Khanmigo can help with that too.

00:00:41.580 --> 00:00:45.420
Feeling iffy about a lesson
that you are about to teach?

00:00:45.420 --> 00:00:47.070
Khanmigo's refresh my knowledge

00:00:47.070 --> 00:00:49.290
will help you prepare for it.

00:00:49.290 --> 00:00:51.360
I can use Khanmigo to help me come up

00:00:51.360 --> 00:00:52.830
with a creative lesson hook

00:00:52.830 --> 00:00:56.460
that gets my students excited
about an upcoming lesson.

00:00:56.460 --> 00:00:58.920
Khanmigo can help me
write learning objectives

00:00:58.920 --> 00:01:00.543
for that unit as well.

00:01:01.800 --> 00:01:03.780
Khanmigo can help me
create a writing rubric

00:01:03.780 --> 00:01:06.540
for my students' next essay or assignment,

00:01:06.540 --> 00:01:08.250
and Khanmigo can write unique,

00:01:08.250 --> 00:01:10.260
thought-provoking exit ticket questions

00:01:10.260 --> 00:01:13.083
that I can use as checks
for understanding.

00:01:14.010 --> 00:01:16.800
I can also use Khanmigo to
collaborate with my students

00:01:16.800 --> 00:01:20.403
to create a fun class summary
poem that I know they'll love.

00:01:21.330 --> 00:01:23.520
Ready to see Khanmigo in action?

00:01:23.520 --> 00:01:25.230
Great, me too!

00:01:25.230 --> 00:01:27.660
I'm gonna start off with
refresh my knowledge

00:01:27.660 --> 00:01:31.860
because next week I'm covering
a unit on the parts of speech

00:01:31.860 --> 00:01:36.007
and it's been a little while,
so I'm just gonna type in,

00:01:36.007 --> 00:01:38.337
"parts of speech."

00:01:39.240 --> 00:01:42.097
I also have to let Khanmigo
know my grade level,

00:01:42.097 --> 00:01:44.007
"7th grade."

00:01:49.380 --> 00:01:51.510
Amazing, with one click of the button,

00:01:51.510 --> 00:01:53.790
Khanmigo is able to give me a overview

00:01:53.790 --> 00:01:55.470
of the five major concepts,

00:01:55.470 --> 00:01:58.320
and then offers to support
me a little bit more

00:01:58.320 --> 00:02:00.900
by offering to quiz me on the topic

00:02:00.900 --> 00:02:03.150
and learn through conversation.

00:02:03.150 --> 00:02:07.110
Now I want to come up with
a creative lesson hook

00:02:07.110 --> 00:02:12.110
for my students, so we
are going to cover nouns.

00:02:14.850 --> 00:02:18.000
These are good, but I would
like to make it funny.

00:02:18.000 --> 00:02:21.570
So Khanmigo, can you make it funny?

00:02:21.570 --> 00:02:25.620
Absolutely, humor is a fantastic
way to engage students.

00:02:25.620 --> 00:02:29.100
I couldn't agree more,
thank you so much, Khanmigo.

00:02:29.100 --> 00:02:32.970
Now, could you help me
create a lesson plan on nouns

00:02:32.970 --> 00:02:35.193
to introduce the topic to my students?

00:02:36.660 --> 00:02:39.453
I would love one on introduction to nouns.

00:02:41.880 --> 00:02:44.310
And again, with one click of a button,

00:02:44.310 --> 00:02:48.663
Khanmigo creates an
incredible lesson plan for me.

00:02:49.530 --> 00:02:52.230
Wow, this is incredible!

00:02:52.230 --> 00:02:54.060
Okay, can we please print this?

00:02:54.060 --> 00:02:56.760
This is amazing!

00:02:56.760 --> 00:02:59.343
Khanmigo included the learning objective,

00:03:00.360 --> 00:03:03.090
the activities that my
students are going to do,

00:03:03.090 --> 00:03:05.340
the exit ticket, key terms,

00:03:05.340 --> 00:03:07.080
the resources that I'm going to need,

00:03:07.080 --> 00:03:09.000
and then a lesson summary.

00:03:09.000 --> 00:03:11.550
This is absolutely incredible.

00:03:11.550 --> 00:03:13.860
In just a few minutes, Khanmigo,

00:03:13.860 --> 00:03:18.000
my new teaching assistant,
has saved me so many hours

00:03:18.000 --> 00:03:21.450
of planning time to help me
create a quality lesson plan

00:03:21.450 --> 00:03:23.310
for my students.

00:03:23.310 --> 00:03:25.260
Incorporating Khanmigo into the classroom

00:03:25.260 --> 00:03:27.660
is going to be a game
changer for teachers.

00:03:27.660 --> 00:03:29.790
Khanmigo's insights and suggestions

00:03:29.790 --> 00:03:31.680
are going to enhance classroom learning

00:03:31.680 --> 00:03:35.400
and make teachers' lives easier
by saving them so much time

00:03:35.400 --> 00:03:36.870
so that we'll have the ability

00:03:36.870 --> 00:03:40.260
to focus on what's
important, our students.

00:03:40.260 --> 00:03:41.523
Thank you, Khanmigo.


Khanmigo: Create a Lesson Plan Activity

WEBVTT
Kind: captions
Language: en

00:00:00.750 --> 00:00:02.010
- This is Khanmigo,

00:00:02.010 --> 00:00:05.730
an AI powered guide designed
to help all students learn.

00:00:05.730 --> 00:00:07.860
Khanmigo is not just for students,

00:00:07.860 --> 00:00:09.630
teachers can use Khanmigo too

00:00:09.630 --> 00:00:11.490
by toggling from the student mode

00:00:11.490 --> 00:00:13.410
to teacher mode in any course.

00:00:13.410 --> 00:00:15.570
And teachers can always access Khanmigo

00:00:15.570 --> 00:00:17.910
by selecting the AI activities button

00:00:17.910 --> 00:00:20.400
located at the top of
the teacher dashboard.

00:00:20.400 --> 00:00:23.430
Khanmigo has many exciting
features that support teachers

00:00:23.430 --> 00:00:26.760
and this video will showcase
ways teachers can use Khanmigo

00:00:26.760 --> 00:00:28.830
to create engaging lesson plans

00:00:28.830 --> 00:00:30.300
to help support their students.

00:00:30.300 --> 00:00:34.500
First, I'm going to go to the
course that I'm working from.

00:00:34.500 --> 00:00:36.000
I'd like to create a lesson plan

00:00:36.000 --> 00:00:38.580
from the digital SAT
Reading and Writing course

00:00:38.580 --> 00:00:41.010
that I'm teaching with my students.

00:00:41.010 --> 00:00:42.930
Our next unit is going to be on

00:00:42.930 --> 00:00:44.880
central idea and details,

00:00:44.880 --> 00:00:47.490
so I'm going to select that.

00:00:47.490 --> 00:00:49.020
And once there, it shows me all

00:00:49.020 --> 00:00:51.450
of the different options
that are in there.

00:00:51.450 --> 00:00:55.290
There's an article, some
videos, as well as an exercise.

00:00:55.290 --> 00:00:57.300
This is where I need Khanmigo's help.

00:00:57.300 --> 00:00:59.610
Once I select Khanmigo's button,

00:00:59.610 --> 00:01:01.860
Khanmigo will give me different options

00:01:01.860 --> 00:01:03.120
that it can help with,

00:01:03.120 --> 00:01:06.060
such as giving me a lesson summary

00:01:06.060 --> 00:01:08.640
or helping me prep for a quiz.

00:01:08.640 --> 00:01:11.760
I would love Khanmigo help
with writing a lesson plan,

00:01:11.760 --> 00:01:13.803
so I'm going to select that.

00:01:15.570 --> 00:01:17.700
And as soon as I select that button,

00:01:17.700 --> 00:01:20.163
Khanmigo starts working.

00:01:21.420 --> 00:01:22.890
Let's take a look at the lesson plan

00:01:22.890 --> 00:01:25.530
that Khanmigo created for me.

00:01:25.530 --> 00:01:27.960
Khanmigo has given me
the learning objectives

00:01:27.960 --> 00:01:29.373
for the lesson plan.

00:01:30.813 --> 00:01:34.230
Khanmigo also created
learning activities for me.

00:01:34.230 --> 00:01:35.760
Actually, Khanmigo created

00:01:35.760 --> 00:01:37.830
three different learning
activities for me.

00:01:37.830 --> 00:01:41.220
Here's an activity on identifying
central idea and details.

00:01:41.220 --> 00:01:43.380
Here's a 20 minute activity.

00:01:43.380 --> 00:01:45.900
This one's a 20 minute activity.

00:01:45.900 --> 00:01:47.760
This one's a 10 minute activity.

00:01:47.760 --> 00:01:49.083
These are great.

00:01:50.130 --> 00:01:52.770
Khanmigo also created exit
ticket questions for me

00:01:52.770 --> 00:01:54.513
that I can use with my students.

00:01:55.920 --> 00:01:58.383
Khanmigo included the key terms.

00:02:00.180 --> 00:02:02.430
Khanmigo also included the resources

00:02:02.430 --> 00:02:04.860
that I'm going to need to
help support my students

00:02:04.860 --> 00:02:06.540
with this lesson.

00:02:06.540 --> 00:02:09.780
Wow, Khanmigo also included
prerequisite videos

00:02:09.780 --> 00:02:11.550
that I can share with my students

00:02:11.550 --> 00:02:14.440
to help give them background
knowledge on the topic

00:02:15.450 --> 00:02:17.940
as well as other differentiation options

00:02:17.940 --> 00:02:21.453
for advanced learners
and striving learners.

00:02:22.620 --> 00:02:25.920
And then finally, Khanmigo's
given me a lesson summary

00:02:25.920 --> 00:02:27.990
over what we're going to be doing.

00:02:27.990 --> 00:02:31.290
Here's the introduction,
activity one, activity two,

00:02:31.290 --> 00:02:33.990
activity three, and then the exit ticket.

00:02:33.990 --> 00:02:37.950
Khanmigo lets me know that this
timeline is a rough estimate

00:02:37.950 --> 00:02:41.760
and I may need to adjust depending
on my student's progress,

00:02:41.760 --> 00:02:43.980
but this is so helpful.

00:02:43.980 --> 00:02:45.750
Khanmigo also gives me the option

00:02:45.750 --> 00:02:48.000
to export this lesson plan

00:02:48.000 --> 00:02:50.103
or I can print the lesson plan.

00:02:52.320 --> 00:02:55.320
And because Khanmigo is truly my co-pilot,

00:02:55.320 --> 00:02:59.250
if there's any part of this
lesson plan that I wanna change,

00:02:59.250 --> 00:03:03.000
Khanmigo will do it for
me, no questions asked.

00:03:03.000 --> 00:03:05.160
I just highlight what I want changed,

00:03:05.160 --> 00:03:09.060
and Khanmigo, my co-pilot,
will give me options

00:03:09.060 --> 00:03:11.163
and then makes the changes for me.

00:03:14.160 --> 00:03:16.080
Thank you so much, Khanmigo.

00:03:16.080 --> 00:03:17.553
This is so helpful.


Introducing Constitution 101 from Khan Academy and the National Constitution Center

WEBVTT
Kind: captions
Language: en

00:00:00.210 --> 00:00:03.090
- [Narrator] Introducing Constitution 101.

00:00:03.090 --> 00:00:06.330
The National Constitution
Center and Khan Academy

00:00:06.330 --> 00:00:09.660
are teaming up to offer
students a free online course

00:00:09.660 --> 00:00:11.640
on the US Constitution,

00:00:11.640 --> 00:00:14.790
led by conversations
hosted by Jeffrey Rosen,

00:00:14.790 --> 00:00:18.390
president and CEO of the
National Constitution Center,

00:00:18.390 --> 00:00:22.140
and Sal Khan, founder
and CEO of Khan Academy,

00:00:22.140 --> 00:00:24.810
joined by dozens of
constitutional scholars,

00:00:24.810 --> 00:00:28.470
professors, and experts from
diverse political philosophies.

00:00:28.470 --> 00:00:29.370
Students will explore

00:00:29.370 --> 00:00:31.920
the constitution's historical foundations,

00:00:31.920 --> 00:00:33.870
landmark supreme court cases,

00:00:33.870 --> 00:00:36.180
and contemporary constitutional issues,

00:00:36.180 --> 00:00:39.360
pioneered by the founders
and diverse figures

00:00:39.360 --> 00:00:41.430
from across American history.

00:00:41.430 --> 00:00:42.600
The semester long course

00:00:42.600 --> 00:00:45.660
will provide non-partisan
constitutional education

00:00:45.660 --> 00:00:48.450
to counter the civics
crisis facing America,

00:00:48.450 --> 00:00:52.380
where civics achievement is
at the same level as 1998.

00:00:52.380 --> 00:00:55.140
Students will gain knowledge
to become engaged citizens

00:00:55.140 --> 00:00:58.290
and foster an understanding
of diverse viewpoints.

00:00:58.290 --> 00:00:59.550
All of the videos,

00:00:59.550 --> 00:01:02.040
quizzes and exercises will be designed

00:01:02.040 --> 00:01:05.160
to align with state curriculum
standards nationwide.

00:01:05.160 --> 00:01:06.870
It's all on Khan Academy.

00:01:06.870 --> 00:01:10.590
And as always, it's free
to anyone, anywhere.

00:01:10.590 --> 00:01:13.620
Khan Academy and the
National Constitution Center,

00:01:13.620 --> 00:01:16.890
shaping the future of
nonpartisan civic education

00:01:16.890 --> 00:01:20.969
with Constitution 101,
launching September, 2024.

00:01:20.969 --> 00:01:23.552
(upbeat music)


Parents: See how to get 24/7 homework help with Khanmigo

WEBVTT
Kind: captions
Language: en

00:00:03.570 --> 00:00:04.440
- [Narrator] Hey, parents.

00:00:04.440 --> 00:00:06.420
Do you need help with
your child's homework?

00:00:06.420 --> 00:00:09.390
Let me show you how Khanmigo
can help with homework today.

00:00:09.390 --> 00:00:12.060
So I'm in Khanmigo and
I'm in the Activities tab,

00:00:12.060 --> 00:00:14.730
and I'm going to use the Tutor Me feature.

00:00:14.730 --> 00:00:17.040
So all you have to do, you or your child

00:00:17.040 --> 00:00:19.260
can copy and paste your
child's homework question

00:00:19.260 --> 00:00:20.430
into Khanmigo.

00:00:20.430 --> 00:00:22.380
For example, let's say I need some help

00:00:22.380 --> 00:00:24.030
with this algebra problem.

00:00:24.030 --> 00:00:26.133
Can you help me solve the equation for X?

00:00:27.120 --> 00:00:28.570
Let's see what Khanmigo says.

00:00:31.500 --> 00:00:33.690
So you can see that Khanmigo's
gonna help me figure it out,

00:00:33.690 --> 00:00:35.820
but it's not going to
just give me answers.

00:00:35.820 --> 00:00:38.490
Instead, it's going to guide
me to find the answer myself,

00:00:38.490 --> 00:00:40.410
which is going to really
help me learn this concept.

00:00:40.410 --> 00:00:42.813
So let's say I think
we need to solve for X.

00:00:45.270 --> 00:00:46.500
And it will encourage me,

00:00:46.500 --> 00:00:48.330
it will give me some
tips on some other things

00:00:48.330 --> 00:00:50.520
that I should consider
to solve this problem.

00:00:50.520 --> 00:00:52.590
Now, if I go to ChatGPT

00:00:52.590 --> 00:00:55.560
and I ask it to help me
with the same problem,

00:00:55.560 --> 00:00:59.160
all, as you can see, it's
only gonna give me the answer.

00:00:59.160 --> 00:01:00.570
But that might not necessarily lead

00:01:00.570 --> 00:01:02.940
to my child really developing
deeper understanding

00:01:02.940 --> 00:01:04.770
and learning of their homework.

00:01:04.770 --> 00:01:06.630
So if you want your kids
to get homework help,

00:01:06.630 --> 00:01:09.300
and really understand the
why behind the answer,

00:01:09.300 --> 00:01:10.590
Khanmigo can help.

00:01:10.590 --> 00:01:13.680
That's because we built
Khanmigo with learning in mind.

00:01:13.680 --> 00:01:15.360
So you wanna give it a try yourself.

00:01:15.360 --> 00:01:17.340
Just click the link in
the description below

00:01:17.340 --> 00:01:18.790
to get started with Khanmigo.