Seen from space, Earth looks blue because so much of it is covered by ocean. About what percent of all the water on Earth is salt water?

Only a small share of Earth's water is fresh water. Where is most of that fresh water found?

Set aside the ice in glaciers and ice caps. Most of the fresh water that is left on Earth is stored where?

Some lakes, such as the Great Salt Lake in Utah, hold salt water instead of fresh water.

A coastal town cannot pipe ocean water straight into homes for drinking. What is the reason?

Nearly all of Earth's salt water is found in one kind of place. Which one?

Earth's fresh water exists, but only a small part of it is easy for people to reach and use. Why is that?

Compared with all the water on Earth, the liquid fresh water sitting in rivers and lakes makes up ___.

The oceans, the glaciers, the lakes, and the groundwater all store water. Which of those four stores holds by far the most water?

Glaciers and ice caps store fresh water, not salt water.

The water flowing in Earth's rivers is salt water.

Some dry countries next to the ocean build plants that remove salt from sea water. What problem are those countries solving?

A table divides Earth's water into 100 equal parts. Almost all of the parts are in the ocean, a couple of parts are in glaciers and ice caps, and just one part is spread across groundwater, rivers, and lakes. What claim do the data support?

Rain falls on a grassy field and soaks down into the soil instead of running off. Where does that water go next?

A town in a dry region pumps its water from wells. After several years with very little rain, the wells start to run low. What best explains this?

Sunshine warms the ocean and some of the water evaporates and rises. What happens to the salt that was dissolved in that water?

Earth's largest ice caps hold huge amounts of frozen fresh water. Where on Earth are they found?

A city builds a dam across a river so that a large lake forms behind it. What problem does this solve for the city?

Groundwater is fresh water held in spaces between soil grains and in cracks in rock underground.

A student leaves two dishes of water on a sunny windowsill until the water is gone. Dish A is left with white crystals; dish B is left almost clean. Which dish held ocean water?