Question

if a neutral atom has a mass of 15 amu and an atomic number of 7, determine the number of protons, neutrons, and electrons in the atom.

Answer 1

Atomic number = amount of protons, so 7 protons.

Because it is a neutral atom, that means that the number of protons has to be the same as the number of electrons. So, there are 7 electrons.

The mass number of an atom, 15, is the total number of protons + neutrons, so 15 - 7 = 8. There are 8 neutrons