OZ - The atmosphere

Question 1

What is the composition of the atmosphere sometimes broken down by?

Answer 1

Its percentage composition by volume of dry air.

Question 2

What does ‘dry air’ mean?

Answer 2

Air with no water vapour in it.

Question 3

What is the percentage concentration of nitrogen in the air?

Answer 3

78%.

Question 4

What does it mean that nitrogen has a percentage concentration of 78% in air?

Answer 4

For every 100 particles in the atmosphere, 78 of them will be N2.

Question 5

What is the percentage concentration of oxygen in the air?

Answer 5

21%.

Question 6

What is the percentage concentration of argon in the air?

Answer 6

~1%.

Question 7

What does ppm stand for?

Answer 7

Parts per million.

Question 8

How do you convert from ppm to percentage concentration?

Answer 8

Divide by 10,000.

Question 9

How do you convert from percentage concentration to ppm?

Answer 9

Multiply by 10,000.

Question 10

How many ppm of CO does the atmosphere contain?

Answer 10

0.1ppm.

Question 11

How many ppm of nitrous oxide does the atmosphere contain?

Answer 11

0.3ppm.

Question 12

What does the sun give out?

Answer 12

Electromagnetic radiation

Question 13

Why does the sun give out electromagnetic radiation?

Answer 13

Because of the processes going on in its core.

Question 14

How is electromagnetic radiation transmitted?

Answer 14

As waves.

Question 15

What type of electromagnetic radiation does the sun give out?

Answer 15

Visible radiation (light) and infrared radiation (heat) along with a smaller amount of ultraviolet radiation.

Question 16

Which EM radiation has the highest frequency&energy?

Answer 16

Gamma rays.

Question 17

Which EM radiation has the lowest frequency&energy?

Answer 17

Radio waves.

Question 18

Order the radiation on the EM spectrum from low to high frequency

Answer 18

Radio waves 
Microwaves
Infrared
Visible light
Ultraviolet
X-rays
Gamma rays

Question 19

Order the radiation on the EM spectrum from high to low frequency

Answer 19

Gamma rays
X-rays
Ultraviolet
Visible light
Infrared
Microwaves
Radio waves

Question 20

What radiation does the Earth’s atmosphere absorb?

Answer 20

Some of the Sun’s infrared radiation and most of the ultraviolet radiation.

Question 21

As well as absorbing some of the Sun’s radiation, what else does the Earth do with it?

Answer 21

The Earth’s surface also absorbs radiation from the sun and is warmed. It the re-emits radiation, mostly as infrared. The Earth emits much lower frequency radiation than the sun (because it’s much cooler).

Question 22

What radiation does the Earth’s surface absorb?

Answer 22

The Earth’s surface also absorbs radiation from the sun and is warmed. It the re-emits radiation, mostly as infrared. The Earth emits much lower frequency radiation than the sun (because it’s much cooler).

Question 23

What do UV and visible light radiation do to electrons?

Answer 23

Give them more energy.

Question 24

Explain how UV and visible light radiation give electrons more energy

Answer 24

The electrons in molecules have fixed energy levels that they can jump between - these are called quantised energy levels.

When UV radiation or visible light hit a molecule of gas the electrons can absorb the energy and jump up and energy level. Because the energy needed for these changes is quantised too, only specific frequencies are absorbed.

If enough energy is absorbed bonds break, forming free radicals.

Question 25

When happens if molecules absorb enough energy from UV radiation?

Answer 25

Bonds break forming free radicals.

Question 26

When happens if oxygen molecules absorb enough energy from UV radiation?

Answer 26

If they absorb the right amount of UV energy they split into oxygen atoms or free radicals - this is the first step in the formation of ozone, O3.

Question 27

What does the energy of light depend on?

Answer 27

Its frequency.

Question 28

What equation can be used to calculate the energy from radiation?

Answer 28

E=hv