Thermal Physics

Chapter 9 - Thermal Properties of Matter

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1. Melting

Change of state from solid to liquid, without a change in temperature.

During melting, temperature remains constant at the melting point. Thermal energy is absorbed by the substance.

2. Solidification

Change of state from liquid to solid, witjout a change in temoerature.

During solidification, the temperature remails constant at the freezing point. Thermal energy is released by the substance.

3. Boiling

Change of state from liquid into vapour (gas), happening at a constant temperature; boiling point.

During boiling, the temperature remains constant at its boiling point. Thermal energy is absorbed by the substance.

4. Condensation

The process where vapour (gas) changes into liquid at a constant temperature. Heat is given out during the process.

During condensation, the temperature remains constant at the condenstion point. Thermal energy is released by the substance.

5. Evapouration

A cooling process

Evapouration of a liquid is due to molecules at the surface with energy greater then the average kinetic energy escaping from the rest of the liquid.

Chapter 9 - Thermal Properties of Matter

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9.1 Internal Energy

Internal Energy is made up of (the sum of) Kinetic energy & Potential energy
An increase in temperature leads to an increase in the Kinetic Component of the Internal Energy.

Chapter 8 - Transfer of Thermal Energy

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Application of Thermal Energy Transfer

Teapot

Cooking Utensils

Greenhouse

Air Conditioner

Chapter 8 - Transfer of Thermal Energy

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8.3 Radiation

1. Continual emission of infrared waves from the surface of all bodies, transmitted without the aid of a medium

2. Infrared radiation is absored by all surfaces, hence causing temperature to rise.

Chapter 8 - Transfer of Thermal Energy

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8.2 Convection

1. Transfer of thermal energy by means of currents in a fluid (liquids/ gases)

2. Occur only in fluids but not in solids.
- because convection involves the BULK movement of the fluids which carry thermal energy with them.

- Thermal energy in solid is transferred from one particle to another through vibrations without any bulk movement of particle themselves.

Chapter 8 - Transfer of Thermal Energy

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8.1 Conduction

- Conduction is the process of thermal energy transfer without any flow

Thermal energy flows through the material of each rod without any flow of the material itself.

Different materials conduct heat at different rates.

Chapter 7 - Kinetic Model of Matter

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7.3 Brownian Motion

Random or irregular motion of smoke particle in air/ pollen grains in water.
When temperature increases, the smoke particles are observed to move faster and more vigorously.
caused by the bombardedment of air molecules on smoke particles/ water molecules on pollen grains in water

Chapter 7 - Kinetic Model of Matter

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7.2 Arrangement & Movement of PARTICLES

Closely Packed together in Regular Pattern,
occupying Minimum space. (High Density)

Vibrate about Fixed Position,

held in position by Strong Intermolecular Bonds.

(Fixed Volume & Shapes)

Randomly arranged with particles slightly
further apart compared to solids.
(Relatively High Density)

Free to move about but Confined,
have Attractive Forces between particles.
(Fixed Volume, No Fixed Shape)

Far Apart, Randomly Arranged. (Low Density)

Particle have Little Attraction between them,
move about randomly at High Speed.
(No Fixed Shape & Volume)

Chapter 7 - Kinetic Model of Matter

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7.1 Properties of Matter

1. Fixed Shape

2. Fixed Volume

3. High Density

4. Incompressible

1. No Fixed Shape

2. Fixed Volume

3. High Density

4. Incompressible

1. No Fixed Shape

2. No Fixed Volume

3. Low Density

4. Compressible