Core Flashcards
(112 cards)
1
Q
What kind of activity do scientist believe formed our early atmosphere?
A
Volcanic
2
Q
Why was the Earth’s early atmosphere believed to similar to that of Titans?
A
Because they believe it was mostly nitrogen and Titan has an atmosphere of 98% nitrogen
3
Q
Why do scientists also believe that the Earth’s early atmosphere was similar to that of Mars?
A
As it was mostly CO2
4
Q
What do scientists believe that volcanoes gave out which later formed the seas as the earth cooled?
A
Water Vapour
5
Q
As seas were formed, what was dissolved?
A
Carbon dioxide
6
Q
What did marine organisms use dissolved CO2 for?
A
Calcium carbonate shells
7
Q
What did the calcium carbonate form when the marine organism died?
A
Sedimentary rock (such as, limestone)
8
Q
When did plants develop the ability to photosynthesise?
A
About 1 billion years ago
9
Q
What is the composition of the current atmosphere?
A
78% nitrogen
21% oxygen
0.04% carbon dioxide
0.9% argon
10
Q
Name a natural way that the atmosphere can change because of
A
Volcanic activity
11
Q
Name the 3 main ways that human activity causes changes in our atmosphere
A
Fossil fuels, farming and deforestation
12
Q
How does farming affect the atmosphere?
A
Both cattle and rice fields give off methane
13
Q
Name the two theories behind nitrogen formation
A
Volcanoes
Nitrogen containing compounds
14
Q
Describe how igneous rock is formed
A
When magma erupts, it becomes lava, and as the lava cools is forms igneous rock containing interlocking crystals
15
Q
What does the size of the interlocking crystals in igneous rock depend on?
A
How quickly the lava cools
16
Q
How is sedimentary rock formed?
A
When the sediment of rocks slowly build up and compress to form layers
17
Q
What are Chalk and Limestone mostly made up of?
A
Calcium carbonate
18
Q
How is metamorphic rock formed?
A
Formed from applying heat and pressure on other rocks for an extended period of time (marble is one example of a metamorphic rock)
19
Q
Name 3 things that limestone is used in/for
A
Glass, cement and concrete
20
Q
Where is limestone removed from?
A
A quarry
21
Q
Name the benefits of a quarry
A
Helps supply reach demand
Creates jobs in countryside
Can improve economy as it is exported to other places
22
Q
Describe the drawbacks of a quarry
A
Dusty and noisy Damage tourist industry Lorises create noise, traffic and more pollution Land can no longer be used for farming Destroys the landscape
23
Q
When calcium carbonate is heated, it decomposed to calcium oxide and co2, what kind of reaction is this?
A
Thermal decomposition
24
Q
How is cement made?
A
Heating limestone and clay
25
How is concrete made?
With cement, sand, gravel and water
26
How is glass made?
By heating limestone with sand and sodium carbonate
27
What does a word equation show?
They show what happens in a reaction
28
What are substances made up of?
Atoms
29
What is the smallest part of an element that can take part in a reaction?
Atom
30
What is a compound?
Atoms of 2+ elements that are chemically joined
31
What does the chemical formula show?
The symbols of the elements and their ratios
32
What does a balanced equation show?
What happens to the atoms in the reaction
33
Describe what happens in a precipitation reaction
Two soluble substances react to form an insoluble product called a precipitate
34
How is limewater made?
By reacting calcium oxide and water to form calcium hydroxide which dissolves to form limewater
35
What is the test for co2?
It will turn limewater milky
36
Explain how carbon dioxide turns limewater milky
Calcium hydroxide and carbon dioxide react to form calcium carbonate and water which is white and insoluble
37
What happens if lots of co2 is bubbled through the limewater and why?
It will turn colourless because the CO2 reacts to form an acidic solution which then reacts with the calcium carbonate
38
What is calcium carbonate used for?
In coal power stations and farming to neutralise gases and soil, therefore it is useful in neutralisation reactions
39
Why do we have HCl in our stomach?
To help digestion (as it provides the correct environment for enzymes to work in) and kill bacteria
40
What is it called when we have too much acid in our stomach and it causes pain?
Indigestion
41
What are the medicines that neutralise stomach acid called?
Antiacids
42
What do Antiacids contain?
Bases that react with acids
43
Describe the reaction between a base and an acid
The acid and base react to form a salt and water
44
In aqueous solution what is the base, acid or alkaline?
Alkaline
45
If an antiacid contains a carbonate what else is produced?
Carbon dioxide
46
What 3 compounds can an acid be neutralised by?
A metal oxide, metal hydroxide and metal carbonates
47
Describe the reaction between an acid and a metal oxide
They reaction to form a salt and water
48
Describe the reaction between an acid and a metal hydroxide
They react to form a salt and water
49
Describe the reaction between an acid and a metal carbonate
They react to form a salt and water and carbon dioxide
50
What salts do sulfuric acid, nitric acid and hydrochloric acid form?
Sulfate, nitrate and a chloride
51
How is chlorine found?
Through electrolysis
52
What is the test for chlorine?
It turns damp blue litmus paper red and then bleaches it
53
Name the uses of chlorine
Water treatment
Manufacture of bleach and other cleaning products
Manufacture of plastics
It is a toxic gas and can kill more people than an explosion
54
What does the electrolysis of water form?
Hydrogen and oxygen
55
What is the test for hydrogen?
The squeaky pop test
56
What is the test for oxygen
It will relight a glowing splint
57
What are the uses of hydrogen
Rocket fuel
58
What are the uses of oxygen
Hospitals
Submarines
Spacecraft
59
Name the top 5 metals in the reactivity series and how they must be obtained as a pure element
Potassium, sodium, calcium, magnesium, aluminium
| Extracted through electrolysis of the molten compound
60
Name the metals that need to be heated with carbon to be extracted as a pure metal
Zinc, iron, tin, lead, copper
61
Name the 3 metals that are found uncombined
Silver, platinum, gold
62
What is metal extraction an example of?
Reduction
63
What is oxidation?
The gaining of oxygen
64
Oxidation results in what?
Corrosion
65
What kind of metals are more likely to corrode?
The more reactive ones
66
What are the advantages of recycling metals?
Natural reserves last longer, less energy needed for recycling than extraction, recycling reduces need for mining, less pollution, less waste minerals
67
What are the disadvantages of recycling metals?
Cost of sorting, collection and recycling is expensive
68
Describe the properties of metals
Shiny when polished, conductors of heat and electricity, malleable and ductile (can be stretched into wires)
69
What are the properties of aluminium?
Low density and doesn't corrode
| It's used for aeroplanes and cars
70
What are the properties of copper?
Good conductors so used in electrics, doesn't react with water so is used in water pipes
71
What are the properties of gold?
It is unreactive and doesn't corrode, it is attractive and malleable so used in jewellery, it is a good conductor so is used in computers and phones
72
What are the properties of iron and steel?
Iron is cheap and easy to extract, it is soft so is turned into steel - a mixture of metals that is used in bridges, cars, electrical goods, machinery and building frames. Also rusts easily
73
What is an alloy?
When a metal is mixed with another to improve its properties
74
What is carat measured out of?
24
75
What is fineness measured out of?
Parts per 1000
76
What is a smart material?
It has properties that change under certain conditions
77
What is a shape memory alloy?
It returns to its original shape heated
78
What are fossil fuels formed from?
They are formed from the compression of sea animals
79
What is crude oil a mixture of?
Hydrocarbons
80
Is crude oil renewable or non renewable?
It's non renewable
81
How is crude oil separated?
In a fractional distillation column
82
Name the fractions from shortest to longest
Gases, petrol, naphtha, kerosene, diesel, fuel and lubricating oil, bitumen
83
What are gases used for?
Fuel for vehicles, bottled gas for camping stoves, heating and cooking
84
What is petrol used for?
Car fuel
85
What is kerosene used for?
Fuel for aircraft
86
What is diesel used for?
Fuel for Diesel engines
87
What is fuel used for?
For large ships and power stations, for heating, for lubricating oil
88
What is bitumen used for?
Making roads, waterproofing roads
89
What is combustion?
When a hydrocarbon burns and reacts with oxygen
90
Combustion of hydrocarbon is only complete if...
All the hydrocarbon is used up
91
What is formed if there isn't enough oxygen in combustion and what is this called?
Carbon monoxide and soot is formed
| This is incomplete combustion
92
Methane and oxygen react to form...
Carbon and water
Carbon monoxide and water
Carbon dioxide, carbon monoxide, water and carbon (soot)
93
Why is carbon monoxide a problem for humans?
It's a colourless, odourless, toxic gas that reduces the amount of oxygen that the body can carry
94
How many people in the UK die each year due to carbon monoxide?
40
95
What is carbon monoxide produced by?
Car engines
96
How is the harm of carbon monoxide reduced?
Making sure all fuel burning appliances are serviced regularly and fitting homes with detectors
97
Name 4 problems of soot..
Clogs pipes and chimneys
Causes fires in chimneys
Collects in the lungs
Makes buildings dirty
98
What is acid rain and what PH must is be below to count as acid rain?
It is acidic due to the gases dissolved in it and must be below 5.2
99
Name one contributor to acid rain
Impurities in hydrocarbons (such as sulfur) which then reacts with oxygen to form sulfur dioxide, an acidic gas
100
Describe the effects of acid rain
Organisms in rivers and lakes and soil are harmed
Damage to trees
Speeds up weathering of limestone/marble and corrosion of metal
101
What is the greenhouse effect?
When gases in air help to trap heat and keep the earth warm
102
Without gases such as CO2, methane and water vapour, what would the mean temperature of earth be?
-18 degrees Celsius
103
What is iron seeding?
Adding iron compounds to encourage plant growth because when animals eat them and die they remove Co2 due to their shells
104
Describe another way that Co2 levels could be reduced
By reacting it into hydrocarbons
105
What are biofuels?
They are positive alternatives to fossil fuels because they are obtained from living organisms or recently dead ones
106
How is ethanol used to create a biofuel
It is mixed with petrol
107
What is diesel biofuel made from?
Vegetable oils
108
What are the advantages of Biofuels?
They are renewable and carbon neutral
109
What are the disadvantages of biofuels?
Not carbon neutral in transport or manufacture and requires a lot of land
110
What is used in a rocket to release energy?
Hydrogen and Oxygen
111
What makes a good fuel?
How easily it burns
How much energy it produces
How easily it is to store and transport
112
Before cars with hydrogen as a fuel can be used what has to happen?
Hydrogen needs to be readily available and filling stations need to be converted
