Lookingg at the periodic table, determine the number of valence electrons present in Phosphorous (P).

a
5 valence electrons
b
4 valence electrons
c
2 valence electrons
d
3 valence electrons

The answer is d) 3 valence electrons. Phosphorous (P) is in group 15 of the periodic table, which means it has 5 valence electrons. However, since phosphorous is in Period 3, it is in the outermost energy level and only has access to the 3rd energy level. Therefore, it has 3 valence electrons in its outermost energy level.