ICSE Class 8 Physics, Unit 1: Matter

What this unit aims at

Building on previous learning in Classes VI and VII, in this class the theme aims at introducing children to the Kinetic Theory which will help them in understanding the difference in the three states of Matter. The theory states that all matter is made of tiny particles which in an object are always in motion that may move slow or fast. In solids, the particles have less energy hence do not move around freely. In liquids, they have relatively more energy and move about freely within the container. The particles of gases have much more energy and move freely at high speeds. The increase or decrease in the movement of energy is the result of heating or cooling of an object. Heating an object increases the energy of particles whereas cooling decreases the energy of particles of an object.

Your child should be able to

• distinguish the three states of matter in terms of movement of particles
• relate the three states of matter with energy of movement of particles in them
• describe the change of state using Kinetic theory:
• Boiling
• Vaporization
• Melting
• Evaporation
• Condensation
• Sublimation
• Deposition

Key concepts in this unit

• Kinetic Theory of Matter.
• Three states of matter in terms of movement of particles.
• Energy content in the three states of matter.
• Change of state in matter using the Kinetic theory:
• Boiling Vaporization Melting
• Fusion Evaporation Condensation Sublimation Deposition Freezing
• Change of state diagrams (using the terms mentioned above).