The following atoms are all variations of the element carbon: 12C, 13C, and 14C due to differing
numbers of neutrons. What are these variations called?
A. Isotopes
B. Polymers
C. Molecules
D.Isomers
Isotopes. Some isotopes of elements that are not usually radioactive are radioactive because they don't have a suitable number of neutrons. For example carbon-12 is stable but carbon-14 is radioactive. Carbon-12 is much more common.
