mass number

A) number of protons > number of electrons
B) number of protons in the atomic nucleus
C) polar; easily dissolves in water
D) number of protons < number of electrons
E) number of protons = number of electrons
F) measure of molecular motion
G) number of protons and neutrons in the atomic nucleus

Mass Number

The total number of protons and neutrons in the nucleus of an atom, which determines its atomic mass.

Protons

Particles with a positive charge found in the nucleus of an atom, playing a role in the atom's mass and total charge.

Neutrons

Subatomic particles found in the nucleus of an atom, with no electric charge and a mass slightly larger than that of protons.