1. The total number of protons and neutrons in the nucleus of an atom is its:
a. atomic number c. mass number
b. Avogadro constant d. number of neutrons
2. As the mass number of the isotopes of an element increases, the number of protons
a. decreases c. remains the same
b. increases d. doubles each time the mass number increases
3. As the atomic number increases, the number of electrons in an atom.
a. decreases c. remains the same
b. increases d. in undetermined
All atoms of the same element have the same
a. atomic mass c. mass number
b. number of neutrons d. atomic numder
