Explain the principle & structure of atom bomb.

Explanation

(i) Atom bomb is based on the principle of uncontrolled chain reaction.
(ii) In an uncontrolled chain reaction, the number of neutrons and the number of fission reactions multiply almost in a geometrical progression.
(iii) Releases huge amount of energy in a very small time interval and leads to explosion.
structure:
(i) Consists of a piece of fissile material whose mass is sub critical.
(ii) This piece has a cylindrical void. It has a cylindrical fissile material which can fit into this void and its mass is also sub critical.
(iii) When the bomb has to be exploded, this cylinder is injected into the void using a conventional explosive.
(iv) Now, the two pieces of fissile material add up to form super critical mass which lead to an explosion.
(v) During theis explosion tremendous amount of energy in the form of heat, light and radiation is released.
(vi) A very high temperature and pressure are formed in a fraction of second along with the emission hazardous radiation like `gamma` rays which adversely affect the living creatures.