Question

Determine the mass number for atoms with the following subatomic makeups 10. 2 protons, 2 neutrons, and 2 electrons

Answer 1

Consider an atom with 2 protons, 2 neutrons, and 2 electrons.

The atomic number is equal to the number of protons, so the atomic number of the above atom is 2.

The mass number is equal to the number of protons plus the number of neutrons. Thus, the mass number of the above atom is equal to two plus two. 

The mass number is 4.