Iron has 2 valence electrons.
Valence electrons refer to the number of electrons that an element has in its outermost shell. This outermost electron is referred to as the ionization power of an atom.
This means the number of electrons the element uses to form chemical bonds with another element.
For elements with an atomic number of above 20, the K, L, M, N formula is traded for the S, P, D, F formula in the representation of subshell electrons.
Using the S, P, D, F formula to represent it, the electronic configuration of iron is:
2, 8, 14, 2.