What is the atomic number of an element that has seven protons and eight neutrons and seven electrons?

Nitrogen has an atomic number of 7 (Z=7) because it has 7 protons in its nucleus. Some nitrogen atoms have an atomic mass number of 15 (A=15). A is the number of neutrons plus protons in the nucleus. However, we already know that there are 7 protons

Atomic number = Number of protons = Number of electrons

Atomic number = 7