PROPERTIES OF WATER
What is water?
Water is a tasteless, odorless and colorless liquid with the chemical formula H2O. Water is all around us. It is the liquid which forms rain, rivers, and the sea and makes up a large part of the bodies of most organisms, including humans.
I know you're probably saying to yourself, duh! I know water is essential but I bet there are a few things about this natural resource that you don't know. You don't believe me!! Well take this short true/false quiz to see if you know all there is to know about water and it's properties.
What makes water so special?
Think of what you need to survive, really just survive. Food? Water? Air? MTV? Naturally, I'm going to concentrate on water here. Water is of major importance to all living things; in some organisms, up to 90 percent of their body weight comes from water. Up to 60 percent of the human body is water, the brain is composed of 70 percent water, and the lungs are nearly 90 percent water. About 83 percent of our blood is water, which helps digest our food, transport waste, and control body temperature. Each day humans must replace 2.4 literes of water, some through drinking and the rest taken by the body from the foods eaten.
There just wouldn't be any you, me, Clifford the dog without the existence of an ample liquid water supply on Earth. The unique qualities and properties of water are what make it so important and basic to life. The cells in our bodies are full of water. The excellent ability of water to dissolve so many substances allows our cells to use valuable nutrients, minerals, and chemicals in biological processes.
States of Water:
Water is unique in that it is the only natural substance that is found in all three states -- liquid, solid (ice), and gas (steam) -- at the temperatures normally found on Earth. Earth's water is constantly interacting, changing, and in movement.
Water as a Liquid
The definition of a liquid is matter which has a definite volume and no definite shape. A liquid takes the shape of its container. In a liquid, the molecules move and slide around each other.
Liquid water is found in many places. You see liquid water coming out of the faucet, when it rains, and running in a river. Pure liquid water is free of salt, rocks, soil, and garbage.
Water as a Solid
When something is solid, like copper, steel, rock, or ice, it is stiff. It does not change shape easily, and it does not change size. In fact, that is the definition of a solid: matter which has a definite volume and a definite shape.
Ice, snow, and frost are examples of water in the solid state. Liquid water freezes at 0 degrees Celsius. Celsius is scale that measures temperature. What instrument do you use to measure temperature? Winter is a season that you see a lot of solid water. Other examples of solid water are ice cubes, icicles, ice on a skating rink.
You don't see anything because gas is invisible. Water in the liquid state may change to water in the gaseous state. Water evaporates to turn into a gas. Gases are colorless and odorless. You cannot see gas, but sometimes you can hear it and smell it. What are some ways that you can hear or smell a gas?
A gas like oxygen, carbon dioxide, helium, or steam can expand to fill any space it is in. If you open a helium balloon, the escaping helium goes everywhere in the room. Gas is matter which has no definite volume (it can be any size) and no definite shape.
Water can evaporate or disappear with the help of heat. Changes in temperature can increase the rate or how long it takes water to evaporate. Evaporate means to disappear. Water can evaporate from soil. It evaporates off wet clothes hanging on a clothesline.
Glossary (all terms dealing with water and its property
Watch the "States of Matter" Video
Additional Water Resources