1. Chemistry 1 warm-up session : Foundation tier

2. Remember, you have learnt all the information on the following slides in your lessons. This is just to refresh your memory of the essentials

3. Atomic structure

4. Atoms have a small central nucleus around which there are electrons

5. A substance that is made of only one sort of atom is called an element
Elements O C C C O O O C C C O O C C C O O
Eg, Carbon is made up of
only carbon atoms
Eg, Oxygen is made up of
only oxygen atoms
A substance that is made of only one sort of atom is called an element

6. Mass number and Atomic number
Number of protons + Number of neutrons 9
Atomic Number =
Number of protons
Number of electrons 4
Elements in the same group in the periodic table have similar chemical properties
Because they have the same number of electrons in their outer shell

7. Electronic structure
1st shell holds a maximum of 2 electrons
2nd shell holds a maximum of 8 electrons
3rd shell holds a maximum of 8 electrons
Electrons are arranged in energy levels or shells around the nucleus.
E.g. An Argon atom has 18 electrons.
We can represent its electron structure as: 2,8,8.

8. Noble gases - Group 8 elements
Noble gases are unreactive because their atoms have stable arrangements of electrons
They have a full outer shell of electrons

9. Chemical reactions

10. Chemical reactions - bonding and electrons
When elements react, their atoms join with other atoms to form molecules and/or compounds.
This is Bonding.
Bonding involves giving, taking or sharing electrons to form ions or molecules

11. Metals bonding with Non-metals
Compounds formed from metals and non metals consist of ions.
Metals lose electrons to form positive ions.
Non metals gain electrons to form negative ions

12. Word and symbol equations+ 
Word equation:
carbon
carbon dioxide
oxygen + 
Symbol equation:
C(s) O2(g)  CO2(g)
Chemical reactions can be represented by word equations or by symbol equations
No atoms are lost or made during a chemical reaction so the mass of products equals the mass of the reactants

13. Limestone Chemical name: Calcium carbonate (alkali)
Chemical formula: CaCO3
Found in earth’s crust - is quarried (dug up)
Uses: Building materials (cement, glass, concrete, mortar); neutralise substances
Heat limestone  breaks down
Thermal decomposition reaction

14. Limestone cycle

15. Quarrying

16. Metals

17. Metal ore Rocks containing metals + other elements
Found in the earth’s crust
Ores contain enough metal to make it economical to extract the metal

18. Unreactive metals found in the Earth as the metal itself
Native metals eg, Gold
Unreactive metals found in the Earth as the metal itself

19. Properties of Transition metals
Like other metals
They are good conductors of heat and electricity
They can be bent or hammered into shape
They are useful as structural materials and for making things that must allow heat or electricity to pass through them easily

20. Alloys are A mixture of elements ...mainly metal...
...containing other elements...
...which change its properties
Steel is an example of an alloy containing iron

21. Why is steel stronger than pure iron?
Pure metals:
have a regular arrangement of atoms – all the same size
Layers can slide over each other
soft and easily shaped
- BUT too soft for many uses.
Alloys/Steel
The different sized atoms :
distort the layers in the structure making it
more difficult for them to slide over each other, and
so alloys (steel) are harder.

22. Why is recycling of metals important?
Saves resources (metal/ore)
Saves energy (extraction)
Cheaper/saves money
Decreases waste material
Decreases (a named) pollutant gas – carbon dioxide/sulphur dioxide

23. Hydrocarbons

24. Crude oil - hydrocarbons
Crude oil consist of molecules made up of hydrocarbons - hydrogen and carbon atoms only

25. Fractional distillation
Crude oil heated
Liquid evaporates
Cools and condenses at different temperatures
Separates into fractions containing similar sized hydrocarbon molecules
Long molecules – bottom
Short molecules - top

26. Alkenes Alkanes Unsaturated hydrocarbons Saturated hydrocarbons
At least one C=C double bond
General formula CnH2n
Saturated hydrocarbons
Each C atom has 4 single bonds
General formula CnH2n+2

27. alkane  alkane + alkene
Cracking
Cracking is a process used to break large hydrocarbon molecules into smaller more useful molecules by
heating them over a
hot catalyst
C10H  C8H C2H4
alkane  alkane alkene

28. Testing for unsaturated compounds (alkenes) – use bromine or iodine

29. Biofuels - ethanol Ethanol can be used as a biofuel
Made either by fermentation with yeast or hydrating ethene (from crude oil)
Adv of using sugar:
- Useful in underdeveloped countries as they can grow sugar cane (have the right climate and enough land)
- sugar is renewable source (oil is non-renewable)
- uses less fossil fuels (low pollution)
Adv of using alkanes:
useful in country which has lots of oil
faster process
economic costs low

30. Acid rain
Greenhouse effect
Burning fuels
Particulates

31. Cause and effects of pollutants
Pollutant found in air
Cause
Effect – environmental problem
Carbon dioxide
Combustion (burning)
Respiration
Greenhouse effect  leads to Global Warming
Carbon monoxide
Incomplete combustion (not enough oxygen)
Blood cannot carry oxygen so well
Sulphur dioxide
Burning coal
Acid rain
Particulates
Burning wood and fossil fuels
Soot deposits
Global dimming
Lung damage
Nitric oxides
High temperature combustion
Smog

32. Polymers and oils

33. Polymerisation
Many small molecules (monomers) join together to form very large molecules (polymers).
Alkenes can be used to make polymers such as poly (ethene) and poly (propene).

34. Uses of polymers
Polymers have many uses and new ones are being developed
E.g. new packaging materials; waterproof coatings for fabrics; hydrogels; and, smart materials (including shape memory polymers)

35. Extracting plant oils
Plant
material
Pressed
or distilled
Water
removed
Crushed
Some fruits, seeds and nuts are rich in oils that can be extracted.
The plant material is crushed
The oil removed by pressing or in some cases by distillation.
Water and other impurities are removed.

36. Emulsions
Emulsions are thicker than oil or water and have many uses that depend on their special properties.
They provide better texture, coating ability and appearance, for example in salad dressings, ice creams, cosmetics and paints.

37. Earth’s structure, movement and atmosphere

38. The Earth’s layers and movement
The Earth’s crust and the upper part of the mantle are cracked into a number of large pieces (tectonic plates)
The Earth consists of a core, mantle and crust.

39. Why can scientists not accurately predict when earthquakes will occur?
Earthquakes involve sudden movements...
...between plate boundaries so...
...scientists are unsure what happens under the crust
...so don’t know where or when the force/ pressure is building up – and reaches its limit

40. Convection currents Convection currents within the Earth’s mantle,
caused by heat released by natural radioactive processes,
cause the plates to move at speeds of a few centimetres per year

41. The Earth’s atmosphere today
For 200 million years, Earth’s atmosphere has been the same as now:
− about 80% nitrogen
− about 20% oxygen
− small amounts of CO2, water vapour and noble gases.

42. How was our atmosphere formed?
First billion years - intense volcanic activity.
Which released the gases that formed the early atmosphere - water vapour that condensed to form the oceans.
There may have been water vapour and small amounts of methane and ammonia.
When plants evolved they produced the oxygen that is now in the atmosphere

43. Some scientific terms... Reliable
Repeating tests, checking results, having a bigger sample
Valid
Keep everything the same except the independent & dependent variables
Precision
Smaller scale division on equipment
Range
From the smallest to biggest
Interval
What the values go up by
Claims
You decide if it is true or false by looking at evidence, independent organisations avoid bias

44. What is the questions asking you to do?
Describe a graph
Refer to the pattern
e.g. as……...increases………increases etc
Explain
Describe & give a reason “because…….”
Evaluate
For & against
Compare
What is the same & what is different
Calculate
Show calculations & give units
Suggest a reason
This should be scientific

45. Things to think about when evaluating a situation...
Economical aspect - money
Environmental – pollution/ greenhouse gases/ global warming/ acid rain/ carbon dioxide/ habitat destruction
Health risks – body rejection/damage
Availability/accessibility
Ethical – suffering/human rights
Religious

46. Some final tips...
Read the whole Q – 33% of the Qs can be answered from information given to you in text, diagrams, graphs & tables
Follow instructions – “tick a box” “tick two boxes” “use info from the table”
Don’t write “it” – “the concentration increases” NOT “it increases”

47. And remember...
1 mark per minute – you have 60 minutes to answer 60 marks
Use bullet points for short questions –
e.g. 3 marks should mean 3 bullet points
Write in ‘good English’ for the 6 mark question
Check your answers – read over your answers at the end

48. Good luck 