1. Revision sheet
Chemistry C1a, Topic 5: Patterns in Properties & Topic 6: Making Changes

2. PERIODIC TABLE Groups Groups 1-2 - Alkali metals
Middle of table - Transition metals
Group 7 Halogens
Group 8 or 0 - Nobel gases/inert elements
transition metals or0
NB: Group 8 - Inert/noble gases are unreactive

3. PERIODIC TABLE SUMMARY
PERIODS – ACROSS GROUPS – GO DOWN H/He – AT THE TOP
Elements in the same group have the similar chemical properties

4. ELEMENTS, ATOMS AND COMPOUNDS
Element has one type of atom in it e.g. Cl2 or H2 or O2
Compound has different elements within it e.g. H2O (hydrogen and oxygen) or NH3 (Nitrogen and Hydrogen)
Atom is just one molecule of an element e.g. Cl or H or O

5. FLAME TEST/Reaction with NaOH
GROUP 1
Potassium- lilac/no precipitate formed
Sodium – yellow/no precipitate formed
Lithium - red flame/white precipitate
Group 2
Calcium - red flame/white precipitate
Barium- green flame
Transition metals
Copper – blue/green/ pale blue precipitate
Lead – blue/white/white precipitate
Iron (II) – pale green precipitate
(Higher – Iron (III) – orange precipitate)

6. TEST FOR THE 5 COMMON GASES
Ammonia – red litmas paper  blue
Chloride – bleaches litmas paper
Carbon dioxide – limewater cloudy
Hydrogen – ‘pop’ with a lit splint
Oxygen – relights a glowing splint
When above is reacted with water
Element + water → Element hydroxide + hydrogen

7. REACTIVITY SERIES Most reactive  least reactive
caesium Cs  rubidium Rb  potassium K sodium Na  lithium Li  calcium Ca magnesium Mg  aluminium Al  zinc Zn  iron Fe  Gold Au  silver Ag
RULE: An metal is more reactive if it is further to the left of the periodic table or further down in the group (not including groups 3-8)

8. METAL ORES Most metals are found in ores
Metal have to be separated from their oxides
They are extracted using two methods (linked to the reactivity series)
Electrolysis – K, Na, Ca, Mg Al (reactive)
Reacting with carbon – Zn, Fe, Sn & Pb (less reactive)

9. TYPES OF REACTIONS PHYSICAL – changing of states
EXOTHERMIC – gives out heat
ENDOTHERMIC – take in heat from it surrounding
THERMAL DECOMPOSITION – is a chemical reaction where a single compound breaks up into two or more simpler compounds or elements when heated
DEHYDRATION – chemical reaction that has water as a product
HYDRATION – have water as a reaction

10. SALTS Chemical name for common salt is sodium Chloride
acids with alkali = neutralisation
oxides, hydroxides and carbonates all react with acids to produce salts
insoluble salts are prepared by mixing two solutions and forms a precipitate
ACID + METAL HYDROXIDE/OXIDE  SALT + WATER = NEUTRALISATION

11. HIGHER - Protons, electrons and neutrons
Number of Protons = atomic number of the element (in top left hand corner of the periodic table)
Number of Electrons = Protons
Number of Neutrons = Mass Number - Atomic Number – Therefore can be different

12. HIGHER - Reactivity Halogens
Fluorine (atomic number 9) > Chlorine (atomic number 17) > Bromine (atomic number 35) >Iodine (atomic number 53)
Therefore chlorine will displace Bromine and Iodine
Same electron in outer shell give similar chemical properties
As the atomic numbers of the halogens increase, they become less reactive