Flowing Water
Welcome to something we like to call the hydrosphere! This is where we talk about the way water moves through the world. Water affects everything that happens in life. In Latin, "hydro" means water. Therefore, anything that scientists describe, when it comes to water, is a part of the HYDROsphere. That water may be at the bottom of the ocean or in the top layers of the atmosphere; it is all a part of the hydrosphere.Water Water Everywhere
Water is in the air, on the land, between the rocks, and in every living thing. Water, in its purest form, is H20 (two hydrogen atoms and one oxygen atom). You will usually find ions or compounds floating around in it, but water is just one small molecule. As you'll discover, it's very busy. While water may move and carry other substances with it, you need to remember that pure liquid water is the thing that makes life on Earth possible.
Liquid water makes the Earth a special place. Our planet has a very nice temperature range that allows water to remain in its liquid state. If we were a colder object like Pluto, it would not matter how much water there was on the planet; it would all be frozen. On the other hand, if we were on a very hot planet, all of the water would be in a gaseous state. Water vapor and solid water are useless to the living organisms found on Earth. Since the hydrosphere includes all of the water on the planet, you will study all of the various states of water. There will be solids in the deep glaciers, liquids of the oceans, and the vapor state of clouds.I Am Water, Hear Me Evaporate
So you're a water molecule. Chances are you'll stay a water molecule and won't ever be broken down. The world likes to keep its water around. Imagine that you're moving through the hydrologic cycle. You evaporate, fall as rain, and drain into a river. There's not a lot of excitement. How much time does it take? Scientists think that if you are lucky enough to evaporate into a cloud, you spend about ten days floating around the atmosphere. If you're unlucky enough to be at the bottom of the ocean or stuck in a glacier, you might spend tens of thousands of years without moving.
