The Atomic Mass of Naturally Occurring Gallium, Which Is a Mixture

Multiple Choice

The atomic mass of naturally occurring gallium, which is a mixture of two isotopes, is listed as 69.723 u. This means that ,Hint: Individual atoms have a mass number that is the sum of the protons and neutrons.

A) all gallium atoms found in nature have a mass that is 69.723/12.000 times as great as that of a ¹²C atom.
B) all gallium atoms found in nature have a mass that is 69.723/1.0079 times as great as that of a ¹H atom.
C) some gallium atoms found in nature have a mass that is 69.723/12.000 times as great as that of a ¹²C atom.
D) some gallium atoms found in nature have a mass that is 69.723/1.0079 times as great as that of a ¹H atom.
E) no gallium atoms found in nature has a mass that is 69.723/12.000 times as great as that of a ¹²C atom.