Water is made up of two elements - hydrogen and oxygen. Each molecules contains 2 parts of hydrogen to 1 part oxygen.
Most of the Earth's water is held in the sea and the seas cover about 70% of the surface of the planet. The rest is in the polar ice caps, rivers, lakes, reservoirs, clouds, sea ice, and locked underground in aquifers.
The water in the sea contains salt so is not drinkable, but the other sources mentioned are mainly fresh and it is this that humans need to drink.
Water is constantly moving around in something that is called The Water Cycle. Basically, water that is exposed to the sun evaporates and the vapour created eventually forms a cloud. When the cloud can hold no more liquid, it rains and the falls back down to Earth, only to start the process all over again.
The balance of water on the planet remains fairly constant, but individual molecules move around, in and out of the atmosphere. Water moves from one reservoir to another and goes through varying phases of solid, liquid and gas.
There are a few processes involved in the water cycle: evaporation, condensation, precipitation, infiltration, subsurface runoff and surface runoff.
The sun powers The Water Cycle with evaporation. Evaporation involves the water taking up energy from the surroundings and subsequently cooling the environment. The liquid water turns into a gas and rises into the atmosphere.
When in the atmosphere, the particles collide and become bigger, forming clouds. This happens through the process of condensation where the gas turns back into a liquid.
Precipitation is the scientific name for rain. It falls onto land, sea, and bodies of fresh water. It can also fall as snow or hail.
Water that falls on the land infiltrates soil and gets down to the groundwater supply, topping it up. The water flows under the surface and find its way to the rivers and sea. The water moving underground is the subsurface runoff.
Other water that falls on the land runs off it into rivers and streams - this is the surface runoff.
It then enters the rivers and seas and will be subject to evaporation again.
There is another way that water can get into the atmosphere and that is through the transpiration of trees. Trees move groundwater from their roots to the pores on their leaves where it evaporates - this process is called evapotranspiration. About 10% of the water in the atmosphere gets there this way. It is then condensed into clouds and falls again because of precipitation.
Water comes from many places on Earth, but it is sure to have been to more places than you think because of The Water Cycle.
Next time you have a glass of water, think about the amazing journey it has taken to get there.
Most of the Earth's water is held in the sea and the seas cover about 70% of the surface of the planet. The rest is in the polar ice caps, rivers, lakes, reservoirs, clouds, sea ice, and locked underground in aquifers.
The water in the sea contains salt so is not drinkable, but the other sources mentioned are mainly fresh and it is this that humans need to drink.
Water is constantly moving around in something that is called The Water Cycle. Basically, water that is exposed to the sun evaporates and the vapour created eventually forms a cloud. When the cloud can hold no more liquid, it rains and the falls back down to Earth, only to start the process all over again.
The balance of water on the planet remains fairly constant, but individual molecules move around, in and out of the atmosphere. Water moves from one reservoir to another and goes through varying phases of solid, liquid and gas.
There are a few processes involved in the water cycle: evaporation, condensation, precipitation, infiltration, subsurface runoff and surface runoff.
The sun powers The Water Cycle with evaporation. Evaporation involves the water taking up energy from the surroundings and subsequently cooling the environment. The liquid water turns into a gas and rises into the atmosphere.
When in the atmosphere, the particles collide and become bigger, forming clouds. This happens through the process of condensation where the gas turns back into a liquid.
Precipitation is the scientific name for rain. It falls onto land, sea, and bodies of fresh water. It can also fall as snow or hail.
Water that falls on the land infiltrates soil and gets down to the groundwater supply, topping it up. The water flows under the surface and find its way to the rivers and sea. The water moving underground is the subsurface runoff.
Other water that falls on the land runs off it into rivers and streams - this is the surface runoff.
It then enters the rivers and seas and will be subject to evaporation again.
There is another way that water can get into the atmosphere and that is through the transpiration of trees. Trees move groundwater from their roots to the pores on their leaves where it evaporates - this process is called evapotranspiration. About 10% of the water in the atmosphere gets there this way. It is then condensed into clouds and falls again because of precipitation.
Water comes from many places on Earth, but it is sure to have been to more places than you think because of The Water Cycle.
Next time you have a glass of water, think about the amazing journey it has taken to get there.
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