Thermal Properties of Matter

heat

The form of energy transferred between two or more systems or a system and its surroundings by virtue of temperature difference

temperature

degree of hotness or coldness of the body

Freezing point

temperature at which pure water freezes

temperature of freezing point

0 degrees Celsius and 32 degrees Fahrenheit

boiling point

The temperature at which pure water boils

Temperature of boiling point

100 degrees Celsius and 212 degrees Fahrenheit

Absolute zero

-273.15 degrees Celsius

thermal expansion

the increase in dimensions of a body due to increase in temperature

types of thermal expansion

1. linear expansion

2. superficial expansion

3. cubical expansion

linear expansion

increase in length on heating

superficial expansion

increase in surface area on heating

cubical expansion

increase in volume on heating

anomalous property of water

on heating from 0 - 4 degreees Celsius it contracts instead of expanding.

On cooling below 4 degrees Celsius, volume of water increases thus density decreases

practical application of thermal expansion

1. a small gap is left between iron rails

2. space is left between griders used for supporting bridges

3. iron ring to be put on the rim of a cart wheel is always of slightly smaller diameter than that of the wheel

4. a glass stopper jammed in the neck of the glass bottle can be removed by warming the neck

Heat capacity

the amount of heat required to raise the temperature of the whole body through I degree Celsius

what does heat capacity depend on?

1. mass of the substance

2. change in temperature

3. nature of the substance

specific heat capacity

amount of heat absorbed or given off to change the temperature of unit mass by one unit