8th Grade Science Final

Question 1

Layers of the atmosphere

Answer 1

1. Troposphere (closest to earth)
2. Stratosphere
3. Mesosphere
4. Thermosphere
5. Exosphere (furthest from earth)

Question 2

Air Pressure

Answer 2

 Because our atmosphere is made up of gases, which have mass, we feel the force of these molecules pushing down on us at the surface of Earth. The molecules of air are more densely packed here because of that force. We are at the bottom of an ocean of air.
 Atmospheric pressure changes with altitude; the more air you have above you the more pressure you will feel. Therefore, the higher you go the less pressure you feel, because earth’s atmosphere is below rather than above you.
 On average a column of air one square inch in cross section measured from sea level to the top of the atmosphere has a mass of 14.7 pounds. This would be equivalent to being under 34 feet of water.

Question 3

High pressure is usually associated with…

Answer 3

good weather

Question 4

Low pressure is usually associated with…

Answer 4

bad weather

Question 5

Jet streams

Answer 5

Occurs in the upper levels of our troposphere.
A channel of fast-moving air.
Creates a boundary between different air masses.

Question 6

What is the greenhouse effect?

Answer 6

A process that happens when Carbon Dioxide is trapped in Earth’s atmosphere (creates heat)

Question 7

Is the Greenhouse Effect a good or bad thing?

Answer 7

It is a good thing because it helps to keep earth warm and alive. It is also bad when there is too much Carbon Dioxide in the atmosphere and it heats earth too quickly.

Question 8

The greenhouse effect: how have humans impacted?

Answer 8

Human emissions impact greatly and can become harmful.

Question 9

The water cycle

Answer 9

the movement of water between the earth and the atmosphere

Question 10

precipitation

Answer 10

the product of condensation in the atmosphere that falls due to gravity

Question 11

condensation

Answer 11

the process of water vapor changing from gas to liquid.

Question 12

transportation

Answer 12

the process by which plants release extra water vapor by evaporation through their leaves.

Question 13

evaporation

Answer 13

the process where liquid changes to a gas

Question 14

2 main gases that make up the troposphere and their %

Answer 14

78% nitrogen
21% oxygen

Question 15

What happens to the sun’s radiation when it hits the atmosphere? (4 things)

Answer 15

1. absorbed by the atmosphere
2. absorbed by the earth’s surface
3. reflected by the atmosphere
4. reflected by earth’s surface

Question 16

where is the ozone layer located?

Answer 16

stratosphere (second layer)

Question 17

chemical formula of the ozone layer

Answer 17

O3

Question 18

Why is the ozone layer important to life on earth?

Answer 18

Ozone absorbs 97-99% of the sun’s high frequency ultraviolet radiation (uv) which is damaging to life on earth.

Question 19

What caused a hole in the ozone layer to form?

Answer 19

Some of the chemicals that are emitted by manmade pollutants, CFS’s, are thought to be responsible for breaking down the ozone layer.

Question 20

High and low pressure

Answer 20

H and L

Question 21

Cold front

Answer 21

blue triangles

Question 22

warm front

Answer 22

red circles

Question 23

stationary front

Answer 23

red circles and blue triangles

Question 24

isobars

Answer 24

connect points of equal pressure on a weather map.

Question 25

isotherms

Answer 25

connect points of temperature (usually color coded)

Question 26

What is a front?

Answer 26

a weather system that is the boundary separating two different types of air.

Question 27

What usually happens at fronts?

Answer 27

When two different air types interact, we get turbulence which creates storms

Question 28

Hurricane

Answer 28

a large, swirling, low pressure system that forms over tropical oceans

Question 29

Sea breeze vs. Land breeze

Answer 29

During the day, the land is warmer, and the ocean is cooler. During night, the land is cooler, and the ocean is warmer.

Question 30

Weather watch

Answer 30

DOES NOT GURANTEE SOMETHING IS GOING TO HAPPEN. Just describes what is likely to happen.

Question 31

Weather warning

Answer 31

a storm exists, this is where it is, this is where it is going. LOOK OUT!

Question 32

Relative humidity

Answer 32

• The “closeness the air is the saturation”
• RH < 40% = feels dry
• RH> 80% = feels moist (humid
• Between 40-80% RH feels comfortable if the temperature is also comfortable.
• It is important to remember that as the temperature increases, the atmosphere has the ability to hold MORE water vapor. The opposite is also true.

Question 33

Rain Shadow Effect

Answer 33

1. As air approaches a mountain, it is forced upward
2. Since atmospheric temperatures drop as elevation increases, the water vapor in this air cools and condenses causing precipitation.
3. By the time the air reaches the other side of the mountains, all of the moisture is gone, and it becomes very arid. (dry)

Question 34

Hail

Answer 34

• Always associated with large, powerful thunderstorms
• Summertime event

Question 35

Sleet

Answer 35

• Winter event
• Sleet is a frozen rain drop

Question 36

Freezing Rain

Answer 36

• As the liquid water hits the surface, it freezes
• The ground must be frozen
• Winter event

Question 37

What is climate?

Answer 37

the average weather in a certain area over long periods of time.

Question 38

How does climate differ from weather?

Answer 38

• Weather is the current conditions of the atmosphere. Climate is the AVERAGE OVER LONG PERIODS OF TIME

Question 39

5 main factors that influence climate for a particular area.

Answer 39

1. Cities
2. Latitude
3. Large Bodies of Water
4. Ocean Currents
5. Mountains

Question 40

Cities

Answer 40

 Create a MICROCLIMATE.
 Have warmer than average temperatures for 2 reasons.
 (1) the materials of a city (concrete, buildings, roads, parking lots) absorb heat and hold heat throughout the day/night.
 (2) Pollution of a city increases the greenhouse effect in city and surrounding areas.

Question 41

Latitude

Answer 41

 Since earth is a sphere, the angle at which the sun strikes the surface varies as you move north or south of the equator.
 The steepness of this angle influences the intensity of the sun’s energy.

Question 42

Large bodies of water

Answer 42

 Have a moderating effect on climate
 Near large bodies of water, winters will be more mild, summers will be cooler
 Large bodies of water can also increase the chance of precipitation.

Question 43

Mountains

Answer 43

 Rain shadow effect (see notes)
 As elevation increases, average temperature decreases

Question 44

What are the three main climate zones on earth?

Answer 44

Polar, temperate, and tropic

Question 45

Polar regions

Answer 45

• sun’s energy arrives at an oblique angle.
• Least amount of sunlight and are therefore frigid
• Ice and snow also reflects a large part of what little sunlight the Polar regions receive

Question 46

Temperate

Answer 46

• Between the tropics and the polar regions.
• The temperatures in these regions are generally relatively moderate
• Most temperate climates have 4 seasons
• Most of the world’s population lives in the temperate zone.

Question 47

Tropic zone

Answer 47

• Warm to hot and moist year-round
• Lush vegetation
• Receives the most direct solar radiation
• Only 2 season, WET AND DRY