Question: What is the role of electrons as part of an atom, and how many electrons do each posess?

Edward Hughes answered on 24 Jun 2014:

Electrons are pretty much responsible for all of chemistry! They allow atoms to stick together to make compounds and molecules via the electromagnetic force. The number of electrons has to be the same as the number of protons in an atom, because overall each atom is neutrally charged. The periodic table arranges atoms in increasing numbers of electrons. So reading the periodic table tells you how many electrons each atom will have!