1. Take about 100 g of ice in a beaker.
2. Suspend a laboratory thermometer so that its bulb is in contact with the ice.
3. Set up the beaker as shown in the figure.
4. Note the temperature.
5. Now heat the beaker slowly
6. Record the change in temperature after every 30 seconds.
7. Let the ice melt completely.
8. Now place a glass rod in the beaker and continue heating till water starts boiling.
9. After some time all the water will get vapourised.
10. From this we understand that substances around us change state from solid to liquid and from liquid v to gas on application of heat.
11. There are some substances which can change directly from solid state to gaseous state and vice versa without changing into the liquid state.