# Question #22638

Aug 19, 2017

The atomic number of${N}_{7}^{15}$
The number of protons is 7
The number of electrons is 7
The number of neutrons is 8

#### Explanation:

The atomic number of Nitrogen is 7 because Nitrogen has 7 protons.
The seven protons attract 7 electrons in the ground state.

If the atom had fewer or more than 7 protons the atom would not be Nitrogen.

The mass of the atom is the sum of protons and neutron. so

$p + n = m a s s$
(protons $\left(p\right)$ and neutrons $\left(n\right)$ both have an atomic mass of slightly larger then one, but for the purpose of this question we shall treeat their mass as equal to one).

Therefore

$7 + n = 15$, subtract 7 from both sides

$7 - 7 + n = 15 - 7$,

$n = 8$, the number of neutrons.