7 electrons, 7 protons, and neutrons
If we are talking about a stable atom of nitrogen (non-isotope), the answer should be 7 for each. The atomic number describes the amount of protons in a molecule, meaning it should have 7 protons.
A single atom should also have an amount of electrons equal to the anount of protons in the atom, meaning it should have 7 electrons. (Now this can vary when it comes to ionic bonds and ions and cations, but I'm assuming this is a normal molecule of Nitrogen).
Now if this is a stable atom of Nitrogen, it should contain 7 neutrons. However, some atoms can be isotopes, meaning they have differing neutrons in their core compared to the stable atom.