Question

Which of the following is reason for radioactivity:
(A) Stable electronic configuration
(B) Stable Nucleus
(C) Unstable Nucleus
(D) Unstable electron configuration

Answer 1

Hint Radioactivity is a phenomenon observed in radioactive elements. Atoms of radioactive elements are unstable and decay into multiple atoms with respect to time. All of the radioactive materials have very high atomic mass and have limited life.

Complete step by step solution
Radioactive elements are unstable and decay into multiple atoms. When an atom decays into multiple atoms, it means its nucleus split into multiple nuclei.
A nucleus is split if it is unstable and unable to hold too many protons and neutrons inside it. This is the main reason due to which only atoms with large atomic mass are unstable.
Then, radioactivity is due to unstable nuclei.

Hence, correct answer is option C.

Note Some of the radioactive elements are good sources of energy and used to produce electricity at nuclear power plants using their property of radioactivity and unstable nucleus. When a radioactive element decays it produces harmful rays which can affect human body and environment in many ways that’s why radioactive waste is put underground to protect the environment and living organisms from its harmful rays.