Here's why:

* Atomic Number: The number of protons defines an element. Nitrogen has an atomic number of 7, meaning it has 7 protons.

* Mass Number: The mass number is the sum of protons and neutrons. In this case, 7 protons + 7 neutrons = 14. Therefore, this atom would have a mass number of 14.

While most nitrogen atoms have 7 neutrons, there are isotopes (atoms of the same element with different numbers of neutrons). So, there could be other isotopes of nitrogen with different numbers of neutrons.