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Question 1

What are the key features of solids?

Answer 1

• Strong forces of attraction between particles.

- Particles vibrate, the hotter they become, the more they vibrate.

Question 2

What are the key features of liquids?

Answer 2

• Forces of attraction weaker than in solids

- Do not keep their shape

Question 3

What are the key features of gases?

Answer 3

• No attraction between particles, free to move.

- Do not keep shape or volume.

Question 4

What is it called when a gas turns into a liquid?

Answer 4

Condensing

Question 5

What is it called when a liquid turns into a solid?

Answer 5

Freezing

Question 6

What is it called when a solid turns into a liquid?

Answer 6

Melting

Question 7

What is it called when a liquid turns into a gas?

Answer 7

Boiling

Question 8

What is an EXOTHERMIC reaction?

Answer 8

A reaction which gives out energy to the surroundings

Question 9

What is an ENDOTHERMIC reaction?

Answer 9

A reaction which takes in energy from the surroundings

Question 10

What is activation energy?

Answer 10

Activation energy is the minimum amount of energy required to start a reaction
-Minimum energy required for bonds to break

Question 11

How can you investigate temperature change? (polystyrene beaker)

Answer 11

-Put a polystyrene cup into a beaker of cotton wool
-Add a first substance to the beaker. Take the temp
-Add a second substance. Take the temp
If the temperature has rised, it is an exothermic reaction.
I the temperature has decreased, it is an endothermic reaction

Question 12

What reaction is bond breaking?

Answer 12

Endothermic

Question 13

What reaction is bond forming?

Answer 13

Exothermic

Question 14

What was phase 1 of the evolution of the atmosphere?

Answer 14

Early atmosphere mostly carbon dioxide with little oxygen.

Volcanic activity released gases like nitrogen, ammonia, methane and water vapour

Question 15

What was phase 2 of the evolution of the atmosphere?

Answer 15

As the earth cooled, the water vapour condensed to form the oceans. Lots of CO2 was removed from the atmosphere as it was absorbed by the oceans

Question 16

What was phase 3 of the evolution of the atmosphere?

Answer 16

Plants and algae started to produce oxygen by photosynthesis.

Question 17

What is the equation for bond energy calculations?

Answer 17

Energy change=energy from reactants-energy from products

Question 18

What evidence is there of the evolution of the atmosphere?

Answer 18

Ancient rocks contain compounds which form when there is hardly any oxygen.

Question 19

What is a combustion reaction?

Answer 19

When you burn a hydrocarbon in oxygen and the only products are Water and Carbon dioxide.

Question 20

What is incomplete combustion?

Answer 20

Incomplete combustion is when there is not enough oxygen.

Question 21

What are the dangers of incomplete combustion?

Answer 21

Produces carbon monoxide, carbon dioxide, soot etc.

Question 22

What are the dangers of carbon monoxide?

Answer 22

Can combine with haemoglobin in red blood cells and stop your blood carrying oxygen round your body.

Question 23

How can sulphur be removed from fuels?

Answer 23

Removing sulfur from fuels uses a lot of energy, releasing Carbon dioxide into the atmosphere.

Question 24

Why is sulfur dangerous when released from fossil fuels?

Answer 24

• When burnt sulfur is oxidised to form sulfur dioxide
• When this acid is mixed with clouds, it forms sulfuric acid, making acid rain which kills plants and damages buildings.

Question 25

What are greenhouse gases?

Answer 25

Gases which ac as an insulating layer to the earth, heating it up

Question 26

What is the greenhouse effect?

Answer 26

- The sun emits electromagnetic radiation - Some of it passes through the atmosphere and is absorbed by the earth - The earth emits long wave radiation which warms up the earth when reflected back at the earth

Question 27

What forms of human activity increase climate change?

Answer 27

Deforestation Burning fossil fuels Agriculture Creating waste

Question 28

What are the consequences of climate change?

Answer 28

Increased in melting of the polar caps-higher sea levels Changes in rainfall patterns More severe storms

Question 29

What methods are there to reduce the amount of greenhouse gas emissions?

Answer 29

- Renewable sources | - Governments could tax/cap companies on emissions

Question 30

Why is making greenhouse gas reductions difficult?

Answer 30

- New technologies have unexpected impacts e.g. Release more carbon dioxide. - Governments may be worried that it could effect the economy

Question 31

WHow can you test for Chorine?

Answer 31

Chlorine bleaches blue litmus paper white

Question 32

How can you test for oxygen?

Answer 32

Glowing splint inside a test tube containing oxygen, it will relight.

Question 33

How can you test for hydrogen?

Answer 33

Squeaky pop test

Question 34

How can you test for Carbon dioxide?

Answer 34

Bubbling CO2 through calcium hydroxide turns the solution cloudy.

Question 35

What is a Hydrogen-Oxygen fuel cell? What are the benefits?

Answer 35

A reaction between hydrogen and oxygen which creates water and energy. - More efficient than power stations. - Don't produce pollutants.

Question 36

How can waste water be made potable?

Answer 36

- It is filtered | - Air is pumped through to increase aerobic bacteria to kill any other impurities

Question 37

How can sea water be made potable?

Answer 37

Leaving a bowl full of sea water in the warm will allow the water to seperate from the salt

Question 38

How is chlorination used to make water potable?

Answer 38

Chlorine gas is bubbled through to kill harmful bacteria.