Topic 7: One-Page Revision Sheet

Chapter 7: Thermal Properties of Matter – One Page Revision

1. Heat

Heat is a form of energy that flows from a body at higher temperature to a body at lower temperature.

SI unit: Joule (J)

2. Temperature

Temperature is the measure of degree of hotness or coldness of a body.

SI unit: Kelvin (K)

Difference Between Heat and Temperature

• Heat is energy, temperature is a measure
• Heat flows, temperature does not
• Heat depends on mass, temperature does not

3. Thermal Expansion

Increase in dimensions of a substance due to rise in temperature.

Types of Thermal Expansion

• Linear expansion – change in length
• Superficial expansion – change in area
• Cubical expansion – change in volume

Linear expansion formula:
ΔL = α L ΔT

4. Specific Heat Capacity

Heat required to raise temperature of 1 kg of a substance by 1°C.

Formula:
Q = m c ΔT

SI unit: J kg⁻¹ K⁻¹

Key Point

• High specific heat → heats up slowly
• Water has high specific heat capacity

5. Calorimetry

Branch of physics dealing with measurement of heat exchange.

Principle:
Heat lost by hot body = Heat gained by cold body

Based on law of conservation of energy.

6. Change of State

Conversion of matter from one physical state to another due to absorption or release of heat.

Latent Heat

Heat absorbed or released during change of state without change in temperature.

Types of Latent Heat

• Latent heat of fusion (solid ↔ liquid)
• Latent heat of vaporization (liquid ↔ gas)

Formula:
Q = m L

7. Important CET Points

• Difference between heat and temperature
• Thermal expansion formulas and applications
• Numericals using Q = m c ΔT
• Principle of calorimetry
• Latent heat concepts and formulas