The atomic number = ? The number of protons = ? The number of electrons on the atomic mass = ? Number of protons ? + Neutrons Meaning that 7 would be the number for the atomic number Nextly, the number of protons would be equal to the 7 for the elections. Then, the number 7 would also be the number for 7. Let's solve this problem out! 15 - (7) which we get the result of 8 Good, luck!