wunder beta🌊 Salt Water and Fresh Water
Almost all of Earth's water is salty ocean. Only a tiny slice is the fresh water we drink. Explore both, and why fresh water is so precious.
What you’ll learn
- The Water PlanetUnderstand that about 97 percent of Earth's water is salt water and about 3 percent is fresh.Earth looks blue because water covers most of it, but almost all of that water, about 97 percent, is salty ocean water. Only about 3 percent is fresh water, the kind found in rivers and lakes that people and land animals drink.
- Salty SeasDefine salt water and explain why the oceans are salty.Salt water is water with lots of dissolved salt, and it fills the oceans. Over millions of years, rivers carried dissolved salt from rock into the sea, and evaporation left the salt behind, so the oceans grew salty. It is too salty for us to drink.
- Precious Fresh WaterDescribe where fresh water is found and why it is precious.The small share of fresh water is even harder to reach than it seems: most is frozen in glaciers and ice, much is underground, and only a tiny bit is in lakes and rivers. Because all land life depends on it, protecting fresh water matters.
Questions this course answers
About how much of Earth's water is salt water?
About 97 percent of all of Earth's water is salty ocean water, leaving only about 3 percent fresh.
Which kind of water do people and land animals drink?
Fresh water has very little salt, so it is the water people, land animals, and plants can drink and depend on.
Why did the oceans become salty over time?
Over millions of years, rivers carried tiny amounts of dissolved salt from rock into the oceans, and evaporation left the salt behind.
Which statement about salt water is true?
Salt water is too salty for people to drink, and it makes up about 97 percent of Earth's water, found in the oceans.
Where is most of Earth's fresh water found?
Most of Earth's fresh water is frozen in glaciers and ice sheets, not in lakes or rivers.
A glacier is made of what kind of water?
Glacier ice is frozen fresh water, which is why most of Earth's fresh water is locked in glaciers.
Grounded in trusted sources
- USGS Water Science School
- NOAA
- National Geographic Kids
- Britannica Kids
Every Wunder lesson is built from real, reputable sources — never invented.
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