ICSE Class 8 Answered

Due to the heat of the Sun, water in the oceans and rivers evaporates and forms water vapour. Moisture is also given out by plants by a process known as transpiration. Water vapour cools down and condenses to form clouds. The water is then precipitated in the form of rainfall, snow or hail. This change of water from one form to the other is known as the hydrological or the water cycle.