Revision

Question 1

What gases are believed to have been released from volcanoes during the first billion years of the Earth’s existence?

Answer 1

Nitrogen, carbon dioxide, water vapour; small amounts of ammonia and methane.

Question 2

How did the oceans form?

Answer 2

Water vapour in the atmosphere condensed.

Question 3

Why did the amount of carbon dioxide in the earlier atmosphere decrease?

Answer 3

When oceans formed, carbon dioxide dissolved in the water; carbonates precipitated producing sediments, reducing carbon dioxide in the atmosphere.

Question 4

How do you test for oxygen gas?

Answer 4

Glowing splint delights

Question 5

What organisms increased the amount of oxygen in the Earth’s atmosphere?

Answer 5

Primitive plants/ algae.

Question 6

Write the balanced symbol equation for photosynthesis.

Answer 6

6CO2 + 6H2O ——————> C6H12O6 + 6O2

Question 7

Other than photosynthesis, what other factors decreased the level of carbon dioxide in the atmosphere?

Answer 7

Formation of sedimentary rocks and fossil fuels (natural gas, oil, coal).

Question 8

Describe the main changes to the atmosphere over time and the likely causes of these changes.

Answer 8

Intense volcanic activity – water vapour, carbon dioxide, nitrogen, ammonia, methane released.
Water vapour condensed to form oceans.
Atmosphere mostly carbon dioxide; nitrogen slowly building up over time.
Carbon dioxide dissolved in oceans; carbonates precipitated producing sediments. Carbon dioxide levels in atmosphere drop.
Photosynthesis – algae produce oxygen.
Plants evolved, levels of carbon dioxide reduced, levels of oxygen increased; animals evolved.
Carbon dioxide levels dropped during the formation of sedimentary rock (from sediments) and fossil fuels (from organisms).

Question 9

Name 3 greenhouse gases.

Answer 9

Water vapour, carbon dioxide, methane.

Question 10

What is the link between greenhouse gases and the temperature of the Earth?

Answer 10

Greenhouse gases maintain temperatures on the Earth high enough to support life.

Question 11

Name human activities which increase the amount of carbon dioxide in the atmosphere.

Answer 11

Burning/ combustion of fossil fuels, deforestation.

Question 12

Name human activities that increase the amount of methane in the atmosphere.

Answer 12

Farming of livestock; landfill sites.

Question 13

What do many scientists believe about human activities and the temperature of the Earth’s atmosphere?

Answer 13

Human activities will cause the temperature of the Earth’s atmosphere to increase at the surface resulting in climate change.

Question 14

Why are there issues surrounding modelling human impact on climate change?

Answer 14

It is difficult to model these changes
There are uncertainties caused by the location where the measurements are taken.
Questions regarding historical accuracy.

Question 15

Name two gases and their compositions in today’s atmosphere.

Answer 15

Nitrogen (80%), Oxygen (20%)

Question 16

Place these metals in order of their reactivity:

Potassium, silver, copper, magnesium

Answer 16

Highest: Potassium, magnesium, copper, silver: lowest

Question 17

Name the two non-metals in the reactivity series.

Answer 17

Carbon and hydrogen

Question 18

Metals form positive ions. What is the scientific name for these positive ions?

Answer 18

Cations

Question 19

Why is gold found in the Earth as an element rather than a compound?

Answer 19

It is very unreactive.

Question 20

What is a redox reaction?

Answer 20

Reaction involving both oxidation and reduction.

Question 21

Describe oxidation in terms of electrons.

Answer 21

oxidation is loss of electrons.

Question 22

Describe reduction in terms of electrons.

Answer 22

reduction is gain of electrons.

Question 23

What is an ore?

Answer 23

Metal compound in a rock.

Question 24

What is produced when metals react with oxygen?

Answer 24

Metal oxide.

Question 25

What is this process called and why?

Answer 25

Oxidation, gain of oxygen.

Question 26

What is reduction in terms of oxygen?

Answer 26

Loss of oxygen

Question 27

What type of ions do metals produce?

Answer 27

Positive

Question 28

Which is more reactive, potassium or iron?

Answer 28

Potassium

Question 29

Which two non-metals can be included in the reactivity series?

Answer 29

Carbon and hydrogen

Question 30

Why is gold found as an element in the Earth?

Answer 30

Unreactive metal

Question 31

How are metals, less reactive than carbon, extracted from their ores?

Answer 31

Reduction with carbon

Question 32

Describe oxidation in terms of electrons.

Answer 32

OIL – loss of electrons

Question 33

Describe reduction in terms of electrons.

Answer 33

RIG – gain of electrons

Question 34

Write the word equation for the reaction between lithium and water.

Answer 34

lithium + water → lithium hydroxide + hydrogen

Question 35

Write the balanced symbol equation for the reaction between lithium and water.

Answer 35

2Li(s) + 2H2O(l) → 2LiOH(aq) + H2(g)

Question 36

HT: Zinc can be extracted from zinc oxide by heating it with carbon in the blast furnace. Carbon monoxide is also produced. Which reactant is:

Answer 36

a) Oxidised? Carbon | b) Reduced? Zinc oxide

Question 37

Why is electrolysis used to extract aluminium from its ore?

Answer 37

Aluminium is more reactive than carbon.

Question 38

Why is electrolysis an expensive way to extract metal from its ore?

Answer 38

Large amounts of energy needed.

Question 39

Name the compound from which aluminium is extracted.

Answer 39

Aluminium oxide/ bauxite.

Question 40

What type of ores can phytomining and bioleaching be used on?

Answer 40

Low-grade ores

Question 41

Why are phytomining and bioleaching used?

Answer 41

Avoids traditional mining methods of | digging, moving and disposing of large amounts of rock

Question 42

How does phytomining extract metals?

Answer 42

Uses plants to absorb metal compounds, the plants are harvested and burned, this produces ash that contains metal compounds.

Question 43

What is a life-cycle assessment?

Answer 43

Considering the impact on the environment for a product; in the lifetime of the product.

Question 44

Life cycle assessments are carried out to assess the environmental impact. What stages of a product are covered?

Answer 44

Obtaining the raw materials Manufacturing the product Using the product Disposal of the product.

Question 45

What areas of life cycle assessments can be easily quantified?

Answer 45

Use of water, resources, energy and waste production.

Question 46

How can metals be recycled?

Answer 46

Melting, recasting or reforming.

Question 47

What are three advantages of recycling metals?

Answer 47

Cheaper, reduced environmental impact, avoids need for mining.

Question 48

Where are most metals found in the periodic table?

Answer 48

Transition metals between Groups 2 and 3

Question 49

Name four properties of transition metals.

Answer 49

High melting point, high density, form coloured compounds, act as catalysts.

Question 50

What is corrosion?

Answer 50

Oxidation of metals.

Question 51

Name three ways to prevent the rusting of iron.

Answer 51

Exclusion of oxygen, exclusion of water, sacrificial protection.

Question 52

What is electroplating? What is it used for?

Answer 52

Using electricity to oat a metal with a thin layer of another metal.

Question 53

What is an alloy?

Answer 53

Metal mixed with other elements.

Question 54

How does converting a metal to an alloy improve the strength?

Answer 54

Distorts the layers in the structure making it difficult for them to slide over each other.

Question 55

What is magnalium?

Answer 55

Alloy of aluminium and magnesium.

Question 56

Name two uses of magnalium.

Answer 56

Aircraft/ car parts, pyrotechnics.

Question 57

How is iron turned into steel?

Answer 57

Addition of carbon and other substances e.g. chromium.