The electrons which are distributed in the outermost shell of the atom are called valence electrons.
These valence electrons can form a chemical bond only if the outer shell remains unclosed.
Valence electrons in an Iron( atom:
The element Iron is in the fourth period and belongs to the -block (group 8).
The atomic number of Iron is 26.
The electronic configuration of Iron can be written as
The valence electrons are the sum of the electrons in the outermost shell, that is six electrons and two electrons which gives a total of eight valence electrons.
Therefore, the valence electron in an Iron(atom is 8.