(i) Radioactive materials should be kept in thick walled lead container.
(ii) Lead coated aprons and lead gloves should be used while working with hazardous radioactive materials.
(iii) We should avoid eating while handling radioactive materials.
(iv) The radioactive materials should be handled only by tongs or by a remote control process.
(v) Dosimeters should be worn by the users to check the level of radiation.

Medical applications of radioisotopes can be divided into two parts
i) Diagnosis ii) Therapy Radio. 
Isotopes are used as tracers to diagnose the nature of blood circulatory disorders, defects of bone metabolism, to locate tumors, etc. Some of the radio isotopes which are used as tracers are: hydrogen, carbon, nitrogen, sulfur, etc.
(i) Radio sodium (Na²⁴) is used for the effective functioning of heart.
(ii) Radio - Iodine (I¹³¹) is used to cure the goiter.
(iii) Radio iron is (Fe⁵⁹) is used to diagnose anemia and also provide treatment for the same.
(iv) Radio phosphorous (P³²) is used in the treatment of skin diseases.
(v) Radio cobalt (Co⁶⁰) and radio gold (Au⁷⁹) are used in the treatment of skin cancer.
(vi) Radiations are used to sterilize the surgical devices as they can kill the germs and microbes.

(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) This releases a huge amount of energy in a very small time interval and leads to explosion.
Structure:
(i) An atom bomb 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 leads to an explosion.
(v) During this explosion tremendous amount of energy in the form of heat, light and radiation is released.
(vi) A very high temperature and pressure are experienced in fraction of second along with hazardous radiation like ૪ rays which adversely affect the living creatures.

1 Bq = one disintegration per second
one curie = 3.7 × 10¹⁰ Bq
1 Bq = \(\frac { 1 }{ 3.7\times { 10 }^{ 10 } } \) curie
∴ 3.7 x 10³ G Bq = 3.7 x 10³ x 10⁹ x \(\frac { 1 }{ 3.7\times { 10 }^{ 10 } } \)
= 100 curie

Dosimeter is a device used to detect the levels of exposure to ionizing radiation. It is frequently used in the environments where exposure to radiation may occur such as nuclear power plants and medical imaging facilities. Pocket dosimeter is used to provide the wearer with an immediate reading of his exposure to X - rays and ૪ - rays.

If the charge of both the nucleus is positive, according to electrostatic theory, when they come closer they tend to repel each other. This repulsive force will be overcome by the kinetic energy of the nuclei at higher temperature of the order of 10⁷ to 10⁹ K.

(i) Extreme high temperature of the order of 10⁷ to 10⁹ K.
(ii) A high pressure to push the hydrogen nuclei closer to fuse with each other.

Ga¹⁵⁰⇾X¹⁴⁶+ ₂He⁴
New atomic number - 146

Beta decay.

The electron of nuclear origin is called a beta - particle. There is otherwise no difference between an electron and a beta - particle.