In chemistry, a<unk>  (Greek:<unk> lon) is an element that readily loses electrons to form positive ions (cations) and has<unk> lic bonds between<unk>  atoms.<unk> s form ionic bonds with non-metals. They are sometimes described as a lattice of positive ions surrounded by a cloud of delocalized electrons. The<unk> s are one of the three groups of elements as distinguished by their ionization and bonding properties, along with the<unk> loids and nonmetals. On the periodic table, a diagonal line drawn from boron (B) to polonium (Po) separates the<unk> s from the nonmetals. Most elements on this line are<unk> loids, sometimes called semi-metals; elements to the lower left are<unk> s; elements to the upper right are nonmetals.
An alternative definition of<unk> s is that they have overlapping conduction bands and valence bands in their electronic structure. This definition opens up the category for<unk> lic polymers and other organic<unk> s, which have been made by researchers and employed in high-tech devices. These synthetic materials often have the characteristic silvery-grey reflectiveness (luster) of elemental<unk> s.
The traditional definition focuses on the bulk properties of<unk> s. They tend to be lustrous, ductile, malleable, and good conductors of electricity, while nonmetals are generally brittle (if solid), lack luster, and are insulators.
Metal
Organic compound
Alkali metal
Phytochemical
Biopolymer
Nutrient
Biomolecule
Biological pigment