Evaporation and Cooling

What happens during evaporation?

• A gas turns into a solid

• A liquid turns into a solid

• A liquid turns into a gas

• A solid turns into a gas

Which particles in a liquid evaporate first?

• The heaviest particles

• The slowest particles

• The particles at the bottom

• The fastest-moving particles

Evaporation can happen best when:

• The liquid is covered

• The air is still and humid

• The surface area is small

• The temperature is high and the surrounding air is moving

Why does evaporation cause cooling?

• The slower particles leave the liquid

• Heat is added to the liquid

• The fast particles escape, taking heat with them

• The liquid turns to solid

You spill water on your hand. After a while, your hand feels cool. Why?

• Water is freezing on your hand

• The water has turned into ice

• The water evaporates, removing heat from your skin

• The water makes your skin wet

Which of the following would increase the rate of evaporation?

• Placing the liquid in the fridge

• Putting the liquid in a narrow cup

• Blowing a fan across the surface of the liquid

• Adding sugar to the liquid

On a windy day, clothes dry faster because:

• The wind cools the clothes

• The wind prevents evaporation

• The wind removes evaporated water vapor

• The wind keeps the clothes warm

Why does sweat help cool the human body?

• Sweat blocks the sun’s heat

• Sweat traps heat under the skin

• Sweat evaporates, taking heat away

• Sweat keeps the body wet

Which condition would lead to the slowest rate of evaporation?

• Warm day with a breeze

• Cold day with no wind

• Hot day with a fan blowing

• Hot day with low humidity

A dish of water is left in the sun and one in the shade. Which will evaporate faster and why?

• The one in the sun, because it is covered

• The one in the shade, because it is cooler

• The one in the sun, because it has more heat energy

• Both will evaporate at the same rate