This PSEB 6th Class Science Notes Chapter 14 Water will help you in revision during exams.
PSEB 6th Class Science Notes Chapter 14 Water
→ Water is a vital resource and is considered a boon to live.
→ Water is present all over the earth.
→ Around the 3/4th part of the earth, the surface is covered with water.
→ The human body consists of 70% of water.
→ We need water for our daily activities and for producing other things.
→ Two main sources of water are surface water and groundwater.
→ Water exists in three states i.e. solid, liquid, and gas.
→ We get water from ponds, lakes, rivers, wells, etc.
→ Sea or Ocean water is salty. It is not fit for drinking and for domestic, agricultural, and industrial needs.
→ As water is a vital resource so it must be conserved.
→ Judicious use of water and saving it is conservation of water.
→ Rainwater is a pure form of water and is safe for drinking.
→ Rainwater harvesting is a technique that conserves water by storage of rainwater. This water can be reused for different useful purposes.
→ The water cycle is a cyclic process in which water is circulated between the earth and the atmosphere.
→ Ocean water supplies water to the water cycle and thus plays an important role.
→ Water from oceans, lakes, wet clothes and plants gets evaporated.
→ Clouds are just the condensation of evaporated water in the air.
→ Clouds cause rains and water returns to earth, oceans, lakes, etc.
→ Snow on mountains melts and water runs into rivers.
→ Water is also absorbed by the ground and becomes available to us as groundwater.
→ Heavy rains and no rains cause too many problems.
→ Heavy rains cause floods which destroy lives and properties.
→ Overflow of water in a large amount beyond its normal limits is known as a flood.
→ A flood is a natural disaster.
→ No rain or very little rain in a region is caused by the drought.
→ In drought conditions availability of food, fodder, and water become negligible.
→ With the increase of population, industries, and agriculture also increase which lay stress on the use of water.
→ Melting: The process of conversion of solid into liquid is called melting.
→ Freezing: The process of converting liquid into solid is called freezing.
→ Evaporation: The process of converting liquid into its vapours is called evaporation.
→ Transpiration: The process by which plants lose their water in the air is called transpiration.
→ Condensation: The process of conversion of water vapours into water is called condensation.
→ Precipitation: Falling of water in the form of rain and snow is called precipitation.
→ Clouds: The condensed water droplets join together to form clouds.
→ Water cycle: The evaporation of water to air, formation of clouds by condensation, and falling of rain on the earth constitutes the water cycle in nature.
→ Rainwater harvesting: Collection of rainwater for use at a time when it is not available otherwise is rainwater harvesting.