With reference to the radioactive decay, consider the following type of decays:
1. The type of decay that causes the number of neutrons in the nucleus to decrease by 1
2. The type of decay that keeps identity of the nucleus unchanged
3. The type of decay that ejects the heaviest particle
Which among the following is the correct set of the types of decays corresponding to above respectively?

Answer: [A] B- decay, Gamma Decay, Alpha decay

When a nucleus undergoes β– decay, a neutron is converted into a proton and an electron, and the electron is ejected. Because of this, the number of neutrons in the nucleus is decreased by 1.

A nucleus in an excited energy state can “relax” to a lower energy state by releasing energy. If the photon(s) emitted in this process are in the gamma-ray portion of the electromagnetic spectrum, we refer to this “decay” as gamma decay. The numbers of protons and neutrons remain unchanged.

When a nucleus undergoes alpha decay, it ejects an alpha particle, which is a helium-4 nucleus, composed of 2 protons and 2 neutrons. This is by far the heaviest decay particle that is ejected from a radioactive nucleus.

This question is a part of GKToday's Integrated IAS General Studies Module