# How can the atomic number be determined?

or, Atomic number = number of ${p}^{+}$ or number of ${e}^{-}$
For example, in one hydrogen atom, number of ${p}^{+} = 1$
$\therefore$ atomic number = 1
In one carbon atom, number of ${p}^{+} = 6$
$\therefore$ Atomic number = 6