Question

Write short notes on induced radioactivity.

Answer 1

The phenomenon by which even light elements are made radioactive, by artificial or induced methods, is called ‘artificial radioactivity’ or ‘man-made radioactivity’. 

This kind of radioactivity was discovered by Irene Curie and F.Joliot in 1934. Artificial radioactivity is induced in certain lighter elements like boron, aluminium etc., by bombarding them with radiations such as ‘alpha particles’ emitted during the natural radioactivity of uranium. This also results in the emission of invisible radiations and elementary” particles. During such a disintegration, the nucleus which undergoes disintegration is called ‘parent nucleus’ and that which is produced after the disintegration is called a ‘daughter nucleus’. The panicle, which is used to induce the artificial disintegration is termed as projectile and the particle which is produced after the disintegration is termed as ejected panicle. When the projectile hits the parent nucleus, it is converted into an unstable nucleus, which in turn decays spontaneously emitting the daughter nucleus along with an ejected particle.

If you denote the parent and daughter nuclei as X and Y respectively, then the nuclear disintegration is represented as follows: 

X (P,E) Y. Here, P and E represent the projectile particle and ejected particle respectively.

₄Be⁹ + ₂He⁴ → ₆C^13*

₆C^13* → ₆C¹² + ₀n¹

In the above nuclear reaction ₆C^13*  is unstable and is radioactive. This reaction can be represented as ₄Be⁹ (α, n) ₄C¹²

₄Be⁹  + ₂He⁴ → ₆C¹² + ₀n¹