Carbon has 6 protons and 6 neutrons for an atomic mass of 12. But there are a some carbon atoms have 8 neutrons (instead of 6). These carbon atoms have a mass of 14 (instead of 12).
What term refers to the fact that in any type of atom some of those atoms have different numbers of neutrons?
Select one:
a. ions
O b. isotopes
O c. neutrons