Unit 2- The Water Planet

Question 1

Why does the Earth have liquid water?

Answer 1

The presence of liquid water on a planet is related to its surface temperature, which depends on two factors:

Question 2

The distance between the planet and its star

Answer 2

Determinate the amount of water radiation it receives.

Question 3

The atmospheric characteristics

Answer 3

Influence the average temperature on the planet

Question 4

How much water is there?

Answer 4

There are roughly 1.3 billion cubic kilometres of water on our planet.

Question 5

The properties of water

Answer 5

It can be found on three physical states of matter: solid liquid and gas.

Question 6

Solid

Answer 6

Is found in snow and glacial ice.

Question 7

Liquid

Answer 7

Is found in oceans, rivers, aquifers, lakes, etc.

Question 8

Gasesous

Answer 8

Is found in the atmosphere.

Question 9

Characteristic 1

Answer 9

Freezes at 0 C and boils at 100 C.

Question 10

Characteristic 2

Answer 10

Water is odourless and colourless

Question 11

Characteristic 3

Answer 11

Ice floats in liquid water.

Question 12

Characteristic 4

Answer 12

It is a great solvent.

Question 13

Is natural water, pure water?

Answer 13

Natural water, both fresh and salty, is not pure water because it always has dissolved substances in it.

Question 14

In solid state, water floats

Answer 14

Unlike the majority of substances, whose density increases during the change of state from liquid to solid, water’s density decreases.

Question 15

A universal solvent

Answer 15

Water dissolves some gases needed for respiration such as oxygen, or for plant nutrition, such as carbon dioxide. All water contains oxygen and nitrogen.

Question 16

Natural air conditioning

Answer 16

Water is essential for maintaining body temperature.

Question 17

Water in the oceans (WITO) pt.1

Answer 17

They are the Earth’s principal water reserves.

Question 18

WITO 2

Answer 18

They form the habitat of a great number of living things.

Question 19

WITO 3

Answer 19

They act as climate moderators.

Question 20

Where does the salt in seas and oceans come from?

Answer 20

Some of the salt in our seas and oceans comes from continental rocks. Salt also comes from underwater volcanic eruptions.

Question 21

The water cycle

Answer 21

The continual circulation of water in nature.

Question 22

Evaporation

Answer 22

The sun heats the water and becomes into gas.

Question 23

Condensation

Answer 23

Water vapour in the air cools down and forms clouds.

Question 24

Precipitation

Answer 24

Gravity makes water fall from the clouds in the form of rain, snow or hail.

Question 25

Infiltration

Answer 25

Some rainwater goes into the ground and becomes subterranean water.

Question 26

Surface run-off

Answer 26

Water that does not evaporate or go into the ground, flows down to form rivers.

Question 27

Transpiration

Answer 27

Living things,return some of the water to the atmosphere as gas.