Water is life and impacts life in so many ways: biologically, chemically, culturally, ecologically, economically, industrially, politically, recreationally, and more.
Water makes life possible
It nourishes the plants we eat and the trees we sit under. It provides habitat for an endless number of living things. There is a limited amount of water on our planet and it gets used over and over again through the water cycle – that is why it is so important to keep it clean! Water connects us all. The same drop of water that flows through the Amazon may end up raining on your town someday. The arctic water a whale swam through could be in your bathtub. Every living thing depends upon water, clean water.
Water is everywhere
The oceans cover more than two-thirds Earth. Even if you are on land, you are likely not far from a stream, river, or lake. The world’s oceans generate most of the oxygen we breathe, help feed us, regulate our climate, offer pharmacopoeia of potential medicines, and clean the water we drink.
Water is NOT an unlimited resource
While 70% of the world is covered by water, only a very small portion of that is accessible fresh water. Most of the fresh water resources are locked up in icecaps and glaciers or hidden underground. Although some scientists speculate that earth may receive small amounts of new water from meteors, the amount of water on our planet is relatively fixed. Humans, plants, and animals have existed on that set amount of water for a long time.
So everything is fine, right? Maybe, or maybe not, when you consider the rising world population, a higher demand for water, and the increase in the amount of water that is so polluted it is unsuitable for use. To add to the problem, freshwater isn’t spread evenly across the planet. Some places like North America have decent water supplies that replenish (if they aren’t overtaxed), but others such as Saudi Arabia and parts of Africa are very dry and face constant water shortages.
Water is H2O
Chemically, Water is H2O. In water, the H stands for Hydrogen and the 2 means there are two parts of hydrogen. The O stands for oxygen. So the recipe for water is two parts hydrogen and one part oxygen.
Water can exist in three forms or phases: liquid, solid, and gas. As a liquid, we know that water is clear, odorless, and tasteless. When water freezes (0°C or 32°F), it takes on its solid form…ice. When water boils (100°C or 212°F), the steam you see is water vapor – the gaseous state of water.
The Water Cycle
There is a limited amount on water on Earth, and so nature uses a water cycle to use every drop of water over again.
Evaporation: Heat from the sun or other sources turns water on the Earth’s surface into a steam or water vapor and it evaporates into the air.
Condensation: The water vapor in the air gets cold and changes back into liquid, forming clouds.
Precipitation: As it cools, the water in clouds becomes heavy and sticks together to form droplets. These droplets then fall back to Earth as rain, hail, sleet, or snow…also known as precipitation.
Collection: When water falls back to earth as precipitation, it may fall back in the oceans, lakes or rivers or it may end up on land. When it ends up on land (or a watershed) it will either soak into the earth and become part of the “ground water” that plants and animals use to drink or it may run over the soil and collect in the oceans, lakes or rivers where it evaporates and the water cycle starts all over again.