Periodicity
Number of shells
Group
Outer shell electron
Group 1 name
Alkali metals
Group 2 name
Alkali earth metals
Group 7
Halogens
Group 8 other name
Noble gasses
5 metal properties
Conducts electricity Metal oxides are bases Shiny High mp/bp Malleable
5 non-metal properties
Don't conduct electricity Non-metal oxides are acidic Dull Low mp/bp Not malleable
3 properties of noble gases
Inert
Colourless
Monatomic gases
Uses of Nobel gases
Helium used in balloons as denser than air
Neon used in advertising signs as glows when electricity is passed through it
Argon used in builds as very unreactive even at high temp so won’t react with the thin metal filament like O2 would
Krypton used in lasers
Properties of alkali metals (6)
Shiny Conduct electricity Soft Low mp/bp Low density React with water
Lithium + water = (and observations)
Lithium hydroxide + hydrogen
Float, move, fizz
Sodium + water = (and observations)
Sodium hydroxide + hydrogen
Float, move, fizz, melt
Potassium + water = (and observations)
Potassium hydroxide + hydrogen
Float, move, lilac flame, violent reaction, fizz
Water + alkali metals turns universal indicator…
Purple (alkali)
Rubidium + water = (and observations)
Rubidium hydroxide + hydrogen
Sinks as denser than water
Immediately reacts with a violent exposition
Caesium + water = (and observations)
Caesium hydroxide + hydrogen
Explodes shattering container
Ions group 1 forms
1+
Explaining trend in group 1 reactivity
Reactivity increases as you go down the group
As you go down the group:
Number of shells increase
Outer electrons further from nucleus
Less strongly attracted
Therefore atom can give up its electrons more easily
What happens to melting point as you go down group 1
Melting point decreases
Fluorine state, colour, use
Gas
Colourless / pale yellow
F– used in toothpaste
Chlorine state, colour, use
Gas, pale green, disinfectant
Bromine state, colour, use
Liquid, red/brown, water purification
Iodine state, colour, use
Solid, silver/black, anti-septic
Astatine state, colour, use
Solid, black, radioactive isotope
Halogen ending, halide ending
ine, ide
Chlorine water aqueous layer
Colourless
Bromine water aqueous layer
Orange
Iodine water colour of aqueous layer
Red/brown
Explaining reactivity in group 7
Reactivity decreases as you go down the group
As you go down the group:
Number of shells increase
Outer shell electrons further from nucleus
This means they are less strongly attracted to the nucleus
Therefore it is more difficult to attract the extra electron into its outer shell
As you go down group 7
Mp increases
Density increases
How to determine percentage of oxygen in air
Passing air in syringe over hot copper turnings
Starting volume - final volume
———————————– x 100
Starting volume
Making and collecting oxygen
Hydrogen peroxide—————-> water + oxygen
Catalyst
H2O2.
Catalyst in making oxygen
Manganese 4 oxide
Percentage of nitrogen in air
78%
Percentage of oxygen in air
21%
Percentage of argon in air
Almost 1%
Percentage of carbon dioxide in air
0.04%
Magnesium burnt in oxygen
Bright white light
White solid
pH 10
Carbon burnt in oxygen
Orange flame and sparks
Colourless gas
pH5
Soulful burnt in oxygen
Melted then burned with a blue flame
Colourless gas
pH1
Metal oxides are…
Bases
Non-metal oxides are…
Acids
Preparation of carbon dioxide
Metal carbonate + acid
CaCO3 + HCl —> CO2 + H2O + CaCl2
How to collect CO2
Over water
Uses of CO2
Fizzy drinks
Fire extinguisher
Use of oxygen
O2 cylinders
Preparation of hydrogen
Metal + acid
Mg + 2HCl —> MgCl2 + H2
Uses of hydrogen
Balloons
Fuel
Metal acid——>
Metal salt + hydrogen
Rust equation
Fe2O3•XH2O
3 ways to prevent rusting
Barrier method
Alloying
Sacrificial protection with a more reactive metal