The stability of an isotope is based on its
(1) number of neutrons, only
(2) number of protons, only
(3) ratio of neutrons to protons
(4) ratio of electrons to protons

Answer=3

The ratio of neutrons to protons generally determine the stability of an isotope.

Atomicity occurs to prevent updates of the database occurring only partially, which can cause greater problems than rejecting the whole series outright.some are monatomic, diatomic, triatomic etc because it shows the number of atoms. for example, monatomic means it contains only one atom.