Practice Problem 2
Classify the following sets of nuclides as examples of either isotopes, isobars, or isotones:
(a) 12C, 13C, and 14C (b) 40Ar, 40K, and 40Ca (c) 14C, 15N, and 16O
Answer
(a) 12C, 13C, and 14C are isotopes because they all contain six protons.
(b) 40Ar, 40K, and 40Ca are isobars because they have the same mass number.
(c) 14C, 15N, and 16O can't be isotopes because they contain different numbers of protons. They can't be isobars because they have different mass number. They all contain eight neutrons, however, so they are examples of isotones.