Question

The spontaneous emission of energy and/or matter from the nucleus of an unstable atom. As a result of this emission, the atom may be converted into an atom of a different element.

Answer 1

As an unstable atom tries to reach a stable form, energy and matter are released from the nucleus. This spontaneous change in the nucleus is called radioactive decay. When there is a change in the nucleus and one element changes into another, it is called transmutation.