How to I need to treat dried green lentils? In the attached picture you see green lentils which I want to prepare in order to make a Dal. They are obviously dried although it is not mentioned directly on the package. 

My question is: Do I need to treat them like dried chickpeas? Dried chickpeas must be unpacked and then stay submerged for around twelve hours to be edible and cookable. Do i need to do the same with the lentils? One lentil has far less mass than a chickpea so I had doubts.

EDIT: I am aware of this possible duplicate but the submitter of the question has not clarified what types of lentils he wants to cook:
Best way to cook lentils?
Your suspicion is correct about "far less mass than a chickpea" means you don't need to soak them as much. Chickpeas seem to need lots of soaking, but you don't have to soak lentils at all. I guess there are lots of kinds of lentils - the kind you have, the big ones with the skins on; the little peeled orange ones; the smaller dark colored ones with skins on, but I don't know of any kind of lentils that need to be soaked at all before cooking. This is the big advantage of lentils over other dried beans: you don't need to plan so far ahead.