Structure & bonding

Question 1

Electron energy levels order

Answer 1

1s 2s2p 3s3p 4s 3d 4p4d4f

Into 4s first, out of 4s first

Question 2

Ionic bonding

Answer 2

Electrostatic force of attraction
between positive ions
& negative ions

Metals attracted to non-metal

Dot & cross diagram
each ion separate

Question 3

Behaviour of giant ionic lattices

Answer 3

Conduct electricity
when molten or dissolved
not when solid
↳ions are mobile in liquid
so carry charge (mobile charge carriers)
position fixed when solid
so cannot carry charge

High melting & boiling points
↳strong electrostatic forces
more energy needed to overcome

High solubility in polar solvents
↳ions broken up by
polar substances

Low solubility in non-polar solvents

Question 4

Covalent bonding

Answer 4

Electrostatic force of attraction
between a shared pair of electrons
& the nuclei of the bonded atoms

Between non-metals

Dot & cross diagram
has connected atoms

Question 5

Dative covalent bonding

Answer 5

Shared pair of electrons
has been supplied
by one of the
bonding atoms only

Question 6

Behaviour of simple molecular lattices

Answer 6

Low conduction of electricity
when solid/liquid/molten
↳no mobile charge carriers

Low melting & boiling points
↳weak intermolecular forces
between molecules

High solubility in polar solvents
if lattice is polar

High solubility in non-polar solvents
if lattice non-polar

Question 7

Giant covalent lattice

Answer 7

No intermolecular forces

Eg. diamond, graphite/graphene, Si, SiO2

Question 8

Behaviour of giant covalent lattices

Answer 8

Low electrical conductivity
except graphite

High melting & boiling points
↳strong covalent bonds
between atoms

Low solubility in polar & non-polar solvents

Question 9

Metallic bonding

Answer 9

Electrostatic force of attraction
between metal ions
& delocalised electrons

Between metals

Diagram has minimum
2 rows of 4 ions in repeating pattern

Question 10

Behaviour of giant metallic lattices

Answer 10

High electrical conductivity
when solid/liquid/molten
↳delocalised electrons
act as mobile charge carriers

High melting & boiling point
↳strong electrostatic attraction
between ions & delocalised electrons

Low solubility in polar & non-polar solvents

Question 11

Explaining differences in melting/boiling points of compounds

Answer 11

1. State structure of each compound
2. Compare relative strengths
3. Compare energy need to overcome
   bonds/intermolecular forces