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Science Launch G5 / Week 10 / Monday
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Week 10 · Water on Earth

Monday

The water planet
// Salty, fresh and frozen
⏱ about 15 min

Monday: The water planet

Rocket spins the classroom globe again. Blue flashes by, again and again.

"Earth is basically one giant water tank," he says. "We will never run out of water to drink."

Raven stops the globe on the Pacific Ocean. "Could you drink this water?" she asks. "What do you notice about the ocean?"

"It is salty," Rocket admits.

Nova projects a tall glass beside the globe. "Would you like a hint?" she asks. "Before you count the water, sort it: salty or fresh."

Mostly water

About 71 percent of Earth's surface is covered with water.

But most of that water is in the oceans, and ocean water is salty.

People need fresh water to drink, to grow food and to keep clean.

Salt water and fresh water

Salt water has a lot of salt dissolved in it. Remember the salt crystals from Week 1?

Fresh water has very little salt. It is found in ice, underground and in lakes and rivers.

This week we will measure how much of each kind Earth has. The answer surprises most people.

FIRST THOUGHTS
  • Read the question.
  • Tap your answer.
About what percent of Earth's surface is covered with water?
Where is most of Earth's water?
StatementTrue or false?
Ocean water is salty.?
Fresh water can be found as ice.?
All of Earth's water is good for drinking right away.?
WHY THIS EXERCISEMost water is salty ocean water, and only fresh water is what people need to drink.
Predict
Before tomorrow, guess: out of every 100 cups of Earth's water, how many are fresh?
Write your guess down. We will check it.

Salty or fresh?

All water is not the same.

Ocean water has a lot of salt dissolved in it.

Fresh water has very little salt. It is found in ice, underground and in lakes and rivers.

SORT THE WATER
  • Read the question.
  • Tap your answer.
A glacier is made of which kind of water?
The Pacific Ocean holds which kind of water?
Which kind of water do people need to drink?
About ____ percent of Earth's surface is covered with water.
Water with very little salt is called ____ water.
OCEAN WATER LEFT IN A DISH
  • ?Pour a little ocean water into a dish.
  • ?Leave the dish in a safe sunny spot.
  • ?The water evaporates over several days.
  • ?Salt crystals are left in the dish.
WHY THIS EXERCISEWhen salt water evaporates, the salt stays behind.
Try it
Write your guess from the Predict box on a sticky note.
Ask a family member to make a guess too.
Tomorrow, see whose guess is closer.
Draw a globe. Color the oceans blue and the land brown. Write about 71 percent water next to it.
For a grown-up
Optional: The Deep Sea by Neal Agarwal scrolls from the ocean surface down to the deepest water.
Type neal.fun/deep-sea into a web browser. It is not a Lantern Learn site.
Its privacy policy says it is not for children under 13. Open it for your child and explore together.

Great start. Tomorrow we will use percents to measure Earth's water.