91Ó°ÊÓ

There appear to be many distinct types of interactions in the world. Planets revolve around stars. In the wind, a falling leaf whirls. A metal rod is bent. Carbon dioxide is formed when carbon and oxygen combine. Uranium nuclei split in nuclear power plants, causing water to boil, which drives electric generators. Despite the multitude of effects we witness, it became obvious in the twentieth century that all of the changes we experience are due to only four types of basic interactions: gravitational, electromagnetic, and gravitational-electromagnetic interactions.

a)

Weak Interaction

All types of elementary particles are affected by the weak interaction. When the neutron is outside of the nucleus is weak interaction between them. If a neutron is removed from the nucleus, the average lifetime of 15 minutes to neutron decays into proton, electron, and antineutrino.

Thus, the neutron outside a nucleus decays into a proton, electron, and antineutrino are weak interactions.

b)

Strong Interaction

The strong or nuclear interaction occurs between things consisting of quarks, such as protons and neutrons, which are kept together in an atom's nucleus despite the protons' strong mutual electric repulsion.

Thus, protons and neutrons attract each other in a nucleus is strong interaction.

c)

Gravitational Interaction

When the attraction between objects with mass is known as gravitational interaction, the earth exerts a gravitational force on the moon and vice versa.

Thus, the Earth pulls on the Moon by gravitational interaction.

(d)

The charged objects encounter electromagnetic interaction when they are in close proximity.

Thus, protons in a nucleus repelling each other are responsible for electromagnetic interaction.