Heat : - Heat is a form of energy.

Temperature : - The temperature of body is defined as the degree of hotness or coldness of that body.

Thermometer : - The device used to measure the temperature of the object is known a s thermometer.

Specific heat : - Specific heat of a substance is defined as the amount of heat required to raise the temperature of unit mass of a substance through 1°c.

Thermal Capacity : - Thermal capacity of an object is defined as the amount of heat needed to raise the temperature of that object through 1°c.

Coefficient of linear expansion : - Coefficient of linear expansion is defined as the increase in length per unit length of the rod when its temperature is raised by 1°c.

Coefficient of superficial expansion : - Coefficient of superficial expansion can be defined as the increase in area per unit area per unit area rise in temperature.

Coefficient of cubical expansion : - Coefficient of cubical expansion is defined as the increase in the volume of solid body per unit volume per unit rise in temperature.

Boiling point : - Boiling point is defined as the temperature at which the vapour pressure is equal to the atmospheric pressure at the liquid surface.

Melting point : - The temperature at which a solid substance is converted into a liquid state is called its melting point.

Latent heat : - Latent heat of a substance is defined as the quantity of heat required by a unit mass of the substance to change its state without change in its temperature.

Fusion : - The process is which a solid changes into a liquid on heating is called fusion or melting.

Latent heat of fusion : - Latent heat of fusion of a solid is defined as the amount of heat required to change unit mass of a substance into liquid state without change in temperature.

Vaporization : - The process in which a liquid changes into a vapour state on heating is called vaporization.

Latent heat of Vaporization : - Latent heat of Vaporization is defined as the amount of heart required to change unit mass of the substance into vapour state without change in temperature.

Evaporation : - The process in which a liquid changes into vapours is called evaporation.

Saturated air : - When maximum amount of water vapour present in air, it is said to be saturated.

Relative humidity : - Relative humidity is defines as the ratio of amount of water vapour actually present in a certain volume of air at a given temperature to the amount of water vapour required.