Chemistry - Chemistry of the atmostphere Flashcards Preview

Year 9 Science > Chemistry - Chemistry of the atmostphere > Flashcards

Flashcards in Chemistry - Chemistry of the atmostphere Deck (36)
Loading flashcards...
1
Q

How long have the proportions of the gasses in the atmosphere been like today

A

200 million years

2
Q

What are the gases and percentages found in today’s atmosphere

A

Nitrogen = 80%
Oxygen = 20%
Other gasses (including carbon dioxide, water vapour and Nobel gases( = <1%

3
Q

What timescale is evidence for the early atmosphere limited to

A

4.6 billion years

4
Q

What planets is the earth’s early atmosphere suggested to be like

A

Mars and Venus, consisted mainly of carbon dioxide and little or no oxygen

5
Q

What other gas were released by volcanoes

A

nitrogen methane and ammonia

6
Q

What are the four ways carbon dioxide is reduced

A
  1. dissolved into the oceans
  2. Plants took it in for photosynthesis
  3. Carbonates precipitated producing sediments
  4. locked in fossil fuels
7
Q

How did the percentage of oxygen increase in the early atmosphere

A

Algae and plants released it during photosynthesis

8
Q

Word equation for photosynthesis

A

Carbon dioxide + water -> glucose + oxygen

9
Q

Describe the greenhouse effect

A
  1. first the sun emits short wavelength radiation which passes through the earths atmosphere and is absorbed by the earths surface
  2. The earths surface emits any excess radiation as long wavelength radiation towards space.
  3. some of the long wavelength radiation makes its way through the earths atmosphere however some do not as greenhouse gasses traps them.
  4. this is then emitted to the earths surface causing it to heat up more resulting in the earths average temperature to increase.
10
Q

When did algae first appear

A

2.7 billion years ago

11
Q

What did the increase in oxygen from algae and plants lead to

A

Enables animals to evolve

12
Q

What useful substances have been formed as carbon dioxide increased

A

Limestone, coal, crude oil and natural gas

13
Q

What type of gas maintains the temperature on earth to be high enough to support life

A

Greenhouse gasses

14
Q

Examples of greenhouse gasses

A

Carbon dioxide
water vapour
methane

15
Q

What greenhouse gases are increased due to human activity

A

carbon dioxide increasing due to
-burning fossil fuels
-deforestation reducing carbon being taken In for photosynthesis

methane increasing due to
-farming cattle
-farming rice paddy fields
-landfill sites (rubbish decomposes and releases methane)
-\swamps

16
Q

What do scientists believe humans activity will do the temperature of the earth

A

Increase it, leading to climate change

17
Q

What is the temperature of the earth increasing normally referred to as

A

Global warming

18
Q

Why is it difficult to predict global warming

A

Based on simply models, speculation and opinion presented in media

19
Q

What is the issue with climate change presented in the media

A

Based on opinion, speculation, only parts of evidence and can be biased

20
Q

What is causing climate change

A

increase in average global temperature

21
Q

What are the main four potential effects of global change

A

glacier and polar ice caps melting
sea levels rising
patterns in rainfall changing
habitats changing

22
Q

What is the carbon footprint

A

the total amount of carbon dioxide and other greenhouse gases emitted over the full life cycle of a product, service or event

23
Q

Major source of atmosphere pollutants

A

combustion of fuels

24
Q

what do most fuels contain

A

Carbon, hydrogen and some contain sulfur

25
Q

How can a carbon footprint be reduced

A

By reducing emissions of carbon dioxide and methane

26
Q

what do particulates contribute to

A

global dimming

27
Q

How are oxides of nitrogen produced when burning a full?

A

High temperature in car engines cause oxygen and nitrogen in the air to react

28
Q

How is sulfur dioxide produced when burning a fuel

A

Fuels contain sulfure as an impurity when the fuel is burnt the sulfur reacts with oxygen to form sulphur

29
Q

What do oxides of nitrogen and sulfur lead to

A

Acid rain respiratory problems

30
Q

What does carbon dioxide contribute to and why

A

global warming as it is a greenhouse gas

31
Q

What are the issues with the production of carbon monoxide

A

it is a toxic gas, prevents blood from carrying oxygen to your cells for respiration

32
Q

Why is it hard to detect if carbon monoxide is formed

A

it Is odourless and colourless so can’t be seen

33
Q

What theory is given for the earth’s early atmosphere?

A

1.First billion years intense volcanic activity released lots of carbon dioxide and water vapour (alongside other gases such as methane, nitrogen and ammonia)

  1. When the Earth cooled the water vapour was able to cool and condensed to form oceans the oceans.
  2. Overtime carbon dioxide levels started to decrease.
  3. Algae and plants evolved
  4. Oxygen levels started to increase and animals were
    then able to evolve
34
Q

Balanced symbol equation for photosynthesis

A

6CO2 + 6H2O -> C6 H12 O6 + 6O2

35
Q

How can we reduce carbon emissions?

A

reduce use of cars (cycle/walk instead)

eat less meat

ensure any trees cut down are replanted

recycle and reuse materials

install solar panels in your home

36
Q

What gases can be released into the atmosphere when fuel is burnt?

A

Carbon dioxide
Water vapour
Sulphur dioxide
Oxides of nitrogen
Others - Particulate (microscopic particles)