Science, Chapter 2, Section 4:Water in the Atmosphere

Question 1

What is humidity

Answer 1

The amount of water vapor in the air

Question 2

What is relative humidity

Answer 2

Amount of water vapor held by air compared with how much it can hold

Question 3

What is the dew point

Answer 3

When air is fully saturated with water vapor and condensation occurs

Question 4

What is evaporation

Answer 4

when water changes from a liquid to a gas.

Question 5

What is condensation

Answer 5

when water changes from a gas to a liquid

Question 6

How is air similar to a sponge?

Answer 6

They can both hold and release water.

Question 7

Define evaporation

Answer 7

the process by which water molecules in liquid water escape into the air as water vapor

Question 8

Describe the water cycle

Answer 8

precipitation is rain from clouds
rain goes into lakes, oceans, streams as run-off
water evaporates from plants into the sky
water that evaporates condenses into clouds

Question 9

Define humidity

Answer 9

a measure of the amount of water vapor in the air

Question 10

Define relative humidity

Answer 10

The percentage of water vapor in the air compared to the maximum amount the air can hold

Question 11

How do you measure relative humidity

Answer 11

with a psychrometer

Question 12

describe a psychormeter

Answer 12

it has 2 thermometers, a wet bulb thermometer and a dry bulb thermometer

Question 13

how do clouds form

Answer 13

They form when water vapor in the air becomes liquid or ice crystals

Question 14

Define condensation

Answer 14

the process by which molecules of water vapor in the air become liquid

Question 15

How does water condense

Answer 15

cold air holds less water vapor than warm air. So, as air cools, the amount of water vapor it can hold decreases

Question 16

Define dew point

Answer 16

the temperature at which condensation begins

Question 17

What happens if the dew point is below freezing

Answer 17

water vapor may change directly into ice crystals

Question 18

What is dew

Answer 18

water that condenses from air onto a cold surface

Question 19

why are the tops of some mountains always covered by clouds

Answer 19

moist air moving up into the air is getting cold because it is less dense and rises with the convection current and forms clouds

Question 20

What happens when water vapor condense out of the air?

Answer 20

It rains

Question 21

What happens as the sun rises and warms the air above a lake

Answer 21

the water droplets evaporate

Question 22

How does a psychrometer work?

Answer 22

The wet bulb thermometer has a cloth covering that is moistened with water. Air is blown over both thermometers. Because the wet bulb thermometer is cooled by evaporation, its reading will drop below the dry bulb thermometer

Question 23

What conditions are needed for clouds to form

Answer 23

cold air, so the water vapor in the air can become liquid water or ice crystals

Question 24

How are condensation and humidity related

Answer 24

Once the air can hold no more water (the humidity) , it will start to condense (or form water) in the form of rain or clouds