Evaporation Vocabulary

1. Focus Question: Where does
the water go when something dries?
Investigation 3 - 1

2. Wet and Dry
 When it rains and the pavement
gets wet, who dries it?
 We’re going to do an investigation
to find out where the water goes.

3. Investigation Set-up
 Place both paper towels in the
water.
 Squeeze out most of the water and
place one towel in each cup.
 Place cups on balance and add
drops of water to lighter cup until
they balance.

4.  Paper towels get wet when people use them
to soak up spills. They can sometimes be used
again if they are dried out. These two towels
are equally wet.
 Watch these for a day to see how fast they
dry.
 To make things a little more interesting, cover
one cup with a lid. Place the second lid
under the other cup so it still balances.
 Sketch the investigation set-up in the Before
box on your observation sheet.

5. Observations
 Sketch the investigation in the After box.
 Take the paper towels out of the cups,
compare them and describe the difference.
 Discuss in your group:

Which side of the balance went up and which
side went down?

What caused one cup to go up and one to go
down?

What happened to the water on the two paper
towels?

6. Evaporation
 The paper towel exposed to air dried out.

The water in the towel changed from liquid water
to water vapor, an invisible gas.

Process by which liquid water changes to water
vapor is called evaporation.
 Water vapor in the open cup evaporated
and escaped into the surrounding air.
 Water in the closed cup was not able to
escape into the air.
 All the original water stayed in the closed
cup.

7.  When the water in the open cup
evaporated, the paper towel got dry.
 Water in the closed cup didn’t evaporate, so
the paper towel stayed wet.
 Wet paper towel is heavier, so that side of the
balance goes down and the side with the dry
paper towel goes up.
 Record your explanations on the notebook
sheet. Include what happened to the
balance, the paper towels, and the water.

8. Vocabulary
 Evaporation - The process by which a liquid,
such as water, changes to a gas
 Water Vapor - The gas state of water

9. Content
 What happens to a wet paper towel in an
open cup?
 What happens to the water in a paper towel
when it evaporates?
 Your questions?
 Homework: Read “Drying Up”, pages 182-183,
take 3-column notes and answer questions.

10. Drying Up Questions

What is water vapor?

Where is water vapor?

What does water vapor look like?

What happens when a wet object gets dry?