Periodicity Flashcards
Define First Ionisation Energy
Energy required to remove one electron from each atom in 1 mole of gaseous positive ions
What three factors increase ionisation energy
Electron Shielding
Atomic radii
Nuclear charge
What happens to ionisation energy across a period
Increases
Nuclear charge increases
Atomic radius decreases
Electron shielding stays the same
What happens to ionisation energy down a group
Decreases
Electron shielding increase
atomic radii increases
nuclear charge increases
What is a metallic bond
Strong electrostatic attraction between positive metal ions and negative delocalised electrons
Properties of Giant metallic latice
High m.p + b.p due to strong electrostatic forces
Insoluble due to strong electrostatic forces
Good conductors as delocalised electrons can move to carry charge
Properties of Giant Covalent Lattice
High m.p + b.p due to strong covalent bonds between atoms
Insoluble due to strong covalent bonds
Only graphene and graphite are conductive
What happens to the solubility of Hydroxides from group 2
Increases down the group
This means more OH- are present and thus more alkaline
What are the uses of group 2 bases
Ca(OH)2 is added to neutralise soil
Mg(OH)2 and Ca(OH)2 are used as antacids
What is the electron configuration of halogens
s2 p5
What is the trend in boiling point for halogens
Increases as you go down,
more electrons
more london dispersion forces
more energy needed
What is the trend in reactivity for halogens
Decreases
Electron shielding increases
Atomic radii increases
Nuclear charge increases
Less nuclear attraction
What colour does bromide form in an organic layer
orange
What colour does Iodine form in an organic layer
Purple
what is disproportionation
When an element has been both oxidised and reduced
What happens when chlorine is added to cold NaOH
Cl2 + 2NaOH -> NaClO + NaCl + H2O
What is the halide ion test
Silver nitrate is added
Cl - white precipitate
Br - cream precipitate
I - yellow precipitate
What is the test for carbonate
Add dilute nitric acid
if there are bubbles it could be a carbonate as CO2 would be released from the reaction
Bubble it through limewater and if it goes cloudy a carbonate is present
Test for sulfate
Add Ba2+ (using BaCl2)
SO4 reacts with barium if present
white precipitate forms
Test for presence of NH4+
Heat with NaOH
NH3 would be produced if NH4 was present
NH3 gas turns pH indicator blue
