1. The atomic number equals the number of
a. protons.
b. neutrons.
c. electrons.
d. protons and neutrons.

2. The atomic weight is equal to the sum of
a. neutrons.
b. protons and neutrons.
c. neutrons and electrons.
d. electrons.

3. The smallest units of matter are
a. molecules.
b. atoms.
c. protons.
d. compounds.