Problem: True or False: the element with electron configuration [Kr] 5 s24d105p2 is a metal.

When finding the identity of the element, you’ll have to identify the atomic number of that element. Recall that every single element in the periodic table has a corresponding atomic number.

The atomic number of an element is always equal to the number of protons of that element. And when the element is neutral (charge = 0), the number of protons is equal to the number of electrons.

Neutral element:          Atomic number = # protons = # of electrons