KINETIC MOLECULAR THEORY OF MATTER

KINETIC MOLECULAR THEORY OF MATTER
According to kinetic theory of matter:
Matter is made of very small particles called MOLECULES. These molecules are in a state of motion. They possess Kinetic Energy. Molecular motion may be translational , rotational or vibrational. These molecules attract each other. As the temperature of a substance is increased , its molecular speed is also increased and vice versa. If a substance is compressed , The K.E of its molecules increases and its temperature rises For latest information , free computer courses and high impact notes visit : www.citycollegiate.com
BROWNIAN MOTION
A famous scientist ROBERT BROWN observed that molecules of a substance are moved in ZIG ZAG path. Their motion is random. They collide with each other and move in a new direction after collision in ZIG ZAG fashion. This type of motion present in the molecules of matter is called "Brownian motion".
Brownian motion
ELASTICITY
The property of solid by virtue of which a solid body recovers its original shape after the removal of an applied force is called "ELASTICITY".
ELASTIC LIMIT
If applied force on a solid is gradually increased, a state is reached after which the material will not return to it original shape even after the removal of applied force. This limit is called "ELASTIC LIMIT". After elastic limit, material is permanently deformed. Different substances have different elastic limit.
STRESS
When a body is deformed, the internal force came into play per unit area to restore it to its original state is called "STRESS" OR "Stress is an opposing force expressed per unit area which resists any change in shape."
Stress is equal to the force per unit area. Mathematically:
or
Stress produces when a body is made to change in length, volume or Shape by the application of an external force