Does the atomic mass come from the masses of both protons and electron

no

Explanation:

For any given isotope, the sum of the numbers of protons and neutrons in the nucleus is called the mass number. This is because each proton and each neutron weigh one atomic mass unit . By adding together the number of protons and neutrons and multiplying by 1 , you can calculate the mass of the atom.

? you expect us to answer this? ? this is your schoolwork, i don't think we can with this, i think it would considering being