Kinetic Theory of Matter

♦ Kinetic means movement and kinetic theory of matter explains the properties in terms of movement of particles.
♦ As the temperature rises the kinetic energy of particles increase.
♦ Hence the motion of the particles increase as the temperature rises.

CHANGE OF STATE OF MATTER

1. Melting:
• Particles gain more energy.
• Particles start to vibrate more faster.
• Particles push each other apart solid expands.
• At the melting point vibration increases so much that the bond (attractive forces) between the particles break.
• Solid changes to liquid.

2. Evaporation:
• Particles gain more energy.
• Particles move faster.
• Particles bump into each other and bounce far apart. Liquid expands at the boiling point the bonds between particles break.
• Liquid changes to gas

3. Condensation:
• Particles loose energy.
• Particles move slowly.
• Particles do not have enough energy t bounce far apart when bumped into each other.
• Particles stay close together, attractive force between particles build up and liquids forms.

4. Freezing:
• Particles loose energy.
• Movements slows down even more except for tiny vibrations. Attractive force between particles become very strong.
• Liquid changes to gas.

5. Sublimation:
When a solid changes directly to a gas without becoming a liquid. EG:- Carbon dioxide(CO2), Iodine (I2)