Atoms of i-131 spontaneously decay when the(1) stable nuclei emit alpha particles
(2) stable nuclei emit beta particles
(3) unstable nuclei emit alpha particles
(4) unstable nuclei emit beta particles

Answer;

(4) unstable nuclei emit beta particles

Atoms of I-131 spontaneously decay when the unstable nuclei emit beta particles.

Explanation;

-Unstable nuclides undergo spontaneous change or the spontaneous decay by emitting radiations to attain stability. Stability of isotopes is based on the ratio of neutrons and protons in its nucleus. Although most nuclei are stable, some are unstable and spontaneously decay, emitting radiation.

b. accuracy of the data matters alot more than its number of digits, organization or amount of detail. quantitative observation is more accepted than the qualitative observation.