Bonding

Question 1

Describe the structure, forces (and energy relating to boiling point) of an ionic compound

Answer 1

Ionic compounds are:
- giant 3D lattice structure
- held together by SEFABOCI
- require lots of energy to overcome the forces, so has a high melting point

Question 2

What does giant and lattice mean?

Answer 2

Giant: does not consist of individual molecules
Lattice: repeating structure

Question 3

Describe the structure, forces, electrical conductivity (and energy relating to boiling point) of C60 Fullerene

Answer 3

C60 Fullerene is a covalent substance:
- with a simple molecular structure
- held together by weak intermolecular forces of attraction
- that do not require a lot of energy to break (low boiling point)
- only 3 bonds in each carbon atom, but 4th electron only moves within each C60 molecule

Question 4

Describe covalent bonds.

Answer 4

Strong electrostatic forces of attraction between two positive nuclei and their shared pair of electrons.

Question 5

Give 3 examples of covalent compounds with simple molecular structures

Answer 5

• Ammonia
• Methane
• Carbon Dioxide

Question 6

Describe the structure, forces, hardness, electrical conductivity (and energy for boiling point) of a diamond

Answer 6

Diamond:
- Giant covalent tetrahedral structure (each carbon atom forms 4 bonds)
- Has strong covalent bonds
- Require a lot of energy to overcome (high boiling point)
- For that reason it is hard
- Does not conduct electricity because no electrons are free to move since are held tightly in covalent bonds

Question 7

Describe the structure, bonds, hardness, electrical conductivity (and energy for boiling point) of graphite

Answer 7

Graphite:
- Giant covalent structure with layers of molecules
- Strong covalent bonds
- Requires a lot of energy to overcome them (high boiling point)
- Has weak intermolecular forces between layers so they can slide over each other, making them soft
- Conducts electricity because delocalised electrons are free to move

Question 8

Describe the structure, bonding, malleability and electrical conductivity of metal compounds.

Answer 8

Metals:
- regular lattice arrangement of positive ions surrounded by a ‘sea’ of delocalised electrons
- held together by strong electrostatic forces between the positive nuclei and negatively charged delocalised electrons
- conduct electricity because delocalised electrons are free to move since
- Malleable because layers of metal ions can slide over each other