Heat is a form of energy

Heat is a form of energy. We can use heat for various purposes in our daily life. We use heat for coming food, keeping our body warm, running vehicles, drying clothes and agricultural products, running factories etc. Thus heat energy is essential for our life. The sun is the major sources of heat. Besides the sun we get heat from fuel, electricity friction and combustion of food. Heat produces various effect on different bodies.

There are some effects of Heat

 Matter exits in three states. They are solid, liquid and gas. The state of matter changes due to heat.

a.       Solid state: A solid matter has fixed shape and volume. Table, duster, stones, pen candle are some example of solid. Ice, snow and wax are also solid which melt due to heat. Sunlight and hot air helps in melting ice and snow. For example, take a few pieces of ice. Place them in a beaker and heat from below. Now observe the changes in the state of ice. Likewise take a candle and burn it. Observe carefully the burning of the candle then you will see the melting of was, the burning of the thread inside the candle etc.

b.      Liquid state: Unlike solids, liquids have no fixed shape and size but it has fixed volume. Water, oil, alcohol, spirit and kerosene are some examples of liquids. When water is cooled it changes into ice. Due to same reason in the cold season, water freezes outside the house. When water is heated, water vaporizes into steam. The other liquids such as oil, alcohol, spirit and kerosene also get converted into steam due to heat.

c.       Gas state: Gas has no fixed shape, size and volume. Air, water-vapor, oxygen, nitrogen, carbon dioxide etc are gasses. Gas is generally colorless. So gas is invisible to us. We cannot see air. When gas is cooled it is converted into liquid. Water vapor converts into water due to cooling. So it is a continuous process.