Question

how is the number of neutrons in the nucleus of an atom calculated? *
add the number of electrons and protons together
subtract the number of electrons from protons
subtract the number of protons from the mass number
add the mass number to the number of electrons

Explanation:

The mass number of an atom is the sum of protons and neutrons in the nucleus. So, to find the number of neutrons, we subtract the number of protons (atomic number) from the mass number.

Answer:

subtract the number of protons from the mass number