The Role of Electrons

By Margot Hulse

Electron Shells

In each atom, there are layers of shells. It is easiest to remember these shells as a pea (shell 1 or K), inside a tennis ball (shell 2 or L), inside a netball (shell 3 or M), inside a beach ball (shell 4 or N). On each shell there are ants (electrons), which stay as far away from each other as possible (electrons repel each other because of their negative charges).

Only 2 ant-electrons can fit on K shell, otherwise they will get to close. L shell can fit up to 8 electrons, M shell can fit up to 18 electrons and N shell can fit up to 32 electrons.


Atoms have an equal amount of electrons and protons making balance on positive and negative charges. If this balance changes it is called charged and turns into an iron. When electrons move from atom to atom, Ions form a chemical reaction. If an atom gains an electron it becomes a positive ion and if it loses an electron it becomes a negative ion.

When a sodium atom meets a chlorine atom, it loses an electron off the outer shell and becomes the sodium ion Na+.