1. Revision
1. Complete starter sheet

2. Command words in the chemistry exam file://localhost/Users/sal/Documents/runnymede/chemistry/chemistry book/Content/Success in the exam/Preparing for your examinations/revision_tips_chem.pdf
Define ... means give the precise meaning of a word, phrase, or physical quantity.
What do you understand by/What is meant by ... is similar to Define.
State ... means give a specific name, value, or other brief answer without explanation or calculation. State and Name are very similar instructions.
List ... means give a sequence of names or other brief answers with no explanation. If the question asks for three points, give only three.
Explain ... Should start with BECAUSE. means give a detailed account of causes, reasons, or mechanisms.

3. Describe ... means what colours, states, bubbles etc OR If you are asked to describe a process, it could mean give a detailed account. you could set the steps out as numbered points. You could include a diagram if that is appropriate.
Describe and explain ... Means what will you see and why- give a detailed account, including causes, reasons, or mechanisms.
Outline ... means give a brief account or summary.
Predict ... means suggest an answer, based on other pieces of information. If your answer is a number, you could write roughly, or about before the number.
Deduce ... means to reach a conclusion from the information given. You should include a sentence to support your answer where you explain your reasoning, or refer to a principle or law that you have learnt.

4. Suggest. means propose a hypothesis or other possible answer
Suggest ... means propose a hypothesis or other possible answer. You may have to use your general knowledge and apply it to a new situation.
Calculate ... find a numerical answer, showing the relevant stages in your working (unless you are instructed not to do so). The question will provide the data you need to complete the cal- culation.
Find ... means ‘work out’. You usually have to do a calculation.
Determine ... It usually means you have to do a calculation, by substituting known values into a formula.
Estimate ... find an approximate value for an unknown quantity. You may need to do a calculation. You should use the term about, approximately, or roughly, in your answer.
Sketch ... means draw freehand. Your sketch can be quite rough, but make sure you show the key points correctly.

5. Revision Chapter 1 key words Ions Solidification Solid Plateau
Particles
Liquid
Heating curve
Random movement
Gas
Cooling curve
Diffusion
Inter-conversions
Kinetic theory
Molecule mass
Boiling
Gas pressure
Distance
Evaporating
Volume and pressure
temperature
Melting
Atoms
Ammonium chloride
Freezing
Molecules

6. Unit 1 changes of state Factors which effect diffusion-
All matter if made of ____________
Brownian motion is the r_______movement of particles suspended in a f______ (i.e. a liquid or gas).
Brownian motion happens when particles that are f_____ to move around
C_______ of P________ make them bounce off each other in different directions to create the random paths we observe the particles taking.
Factors which effect diffusion-
Temperature (the higher the temperature the faster a gas will diffuse)
-Density (the lower the relative molecular mass, the faster a gas will diffuse)
Description
Fixed volume, own shape particles touching
Fixed volume, takes shape of container, touching but can move
Any volume, shape of container
Particle arrangement
Regular lattice
random
Particles motion
Vibrate in fixed position
Slow, random, slide over each other
Fast, random
Forces between particles
Strongest
Some forces
Virtually no forces
Equation for reaction
Why the ring forms close to one end
What causes gas pressure ?
What factors effect gas pressure ?

7. Description
Fixed volume, own shape particles touching
Fixed volume, takes shape of container, touching but can move
Any volume, shape of container
Particle arrangement
Regular lattice
random
Particles motion
Vibrate in fixed position
Slow, random, slide over each other
Fast, random
Forces between particles
Strongest
Some forces
Virtually no forces

8. Unit 2 separation techniques
Unit 1 key words
Volatile
Mixture
Purity
Solvent
Impurity
Solute
Purity and melting/boiling points
Soluble
Insoluble
aqueous
Sparingly soluble
Temperature
Mixture
method
Filtration
Solid from liquid
Crystallization
Solute from its solution
evaporation
Simple distillation
Solvent from its solution
Fractional distillation
Mixture of Liquids from each other
Paper chromatography
Substances from a solution

9. Chapter 2 name name name Used to separate
When you want to keep the______
e.g.
Used to separate
When you want to keep the________
e.g.
name
Used to separate
e.g.
name
name
Use locating agent for colourless substances (e.g. amino acids.)
Used to separate
e.g.
Used to separate
e.g.
Rf value retention factor = distance moved by substance
distance moved by solvent
Then we can look up these values
Use to separate
e.g.

13. Chapter 3 key words Atoms Neutrons Sterilization Elements Electrons
Carbon dating
Group
Isotopes
Electron arrangement
Period
Radioactivity
Metals and non-metals
Oder of atomic number
Radiation sickness
Check for leaks
Nucleons
Protons
Radiotherapy

14. Chapter 3 Now draw an atom of nitrogen. 14 7 What are isotopes?
What is Ar of Magnesium
Isotope % abundance Mg Mg Mg
Now draw an atom of nitrogen. 14 7
How many electron shells does cesium have ?_________
How many electrons does iodine have in its outer shell ? ________
On the periodic table atoms arranged in order of increasing __________
Atoms in the same___________ have similar properties.
Column=__________
_______= period
Elements in the same group have the same number of ________ in their outer shell.
Elements in the same period have the same number of ________ _____
Subatomic particle
Charge
Mass
Where is it found
proton
nucleus
neutron 1
electron -1

15. Chapter 4 key words Ions Dot and cross Diamond Ionic bonds
Simple covalent MOECULES
Graphite
Giant ionic lattice
Silicon dioxide
Low melting and boiling points
Metallic bonds
Conduct when aqueous
Giant metallic lattice
Weak forces between molecules
High melting and boiling points
Giant covalent lattice (macromolecules)
Compound ions
Covalent bonds

17. Melting and boiling point: giant structures
Substances with giant structures generally have high melting and boiling points because all the atoms are strongly bonded together to form a continuous 3D lattice. A large amount of energy is needed to break these bonds.
strong covalent bonds holds atoms together
strong metallic bonds holds ions together
strong ionic bonds holds ions together

18. Ionic bond=metal and non-metal
The electrostatic attraction between oppositely charged ions
Metal loses electrons to become positive (cation)
Non-metal gains to become negative (anion) 2+ -
ATOM
ATOM Cl Be Cl Be
Be 2,2
Cl 2,8,7
Be2+ [2] 2+
Cl- [2,8,8] -

19. Ionic bonds ALWAYS FORM GIANT IONIC STRUCTURES not molecules
High m.p. and b.p.- lots of strong ionic bonds in the giant ionic lattice, lots of energy to break.
Conducts electricity when dissolved or molten- free moving ions, can conduct (solid= ions in fixed position cannot move)
Soluble in water-water is polar so opposite charges attract ions out of the lattice.

20. Covalent bond=non-metal and non-metal
The electrostatic attraction between a shared pair of electrons and two nuclei
Atoms share up to 3 electron pairs to complete outer shell
Learn dot and cross for, O2, H2, Cl2, H2O, CH4, NH3 , HCl , N2, C2H4, CH3OH and CO2

21. Simple covalent molecules e. g
Simple covalent molecules e.g. O2, H2, Cl2, H2O, CH4, NH3 , HCl , N2, C2H4, CH3OH and CO2
Gases and liquids at room temperature, low m.p. and b.p.- ONLY weak forces of attraction between molecules. Do not conduct – no free ions or electrons

22. Giant covalent structures
Uses
drilling-its very hard
Jewelry-shiny
Uses
pencils-soft and dark (makes a mark on the page)
Lubricant-only weak forces between the layers, can easily slip and slide over each other.

23. Copy: Metal Structure
Definition of a metallic bond -the attraction between the array of positive metal ions and the sea of delocalised electrons.
Why ? All metal atoms are arranged in a regular pattern - Lattice
Metal atoms have tendency to loose electrons to become stable
Delocalised electrons from outer shells of metal
Conduct heat
Conduct electricity

24. Examples of Alloys Different types of steel Steel = IRON + CARBON
= IRON + CARBON + Chromium / Nickel
= IRON + CARBON + Manganese

25. Brass = Copper + Zinc.
Bronze = Copper + Tin
Solder = Zinc + Lead
Amalgam = Mercury + Silver

26. When you hit the metal, the layers can slide….. Metal
force
But for alloys, when you hit, the layers cannot slide…..because the atoms are of different size!!
So More STRONG than metals
force