C2

Question 1

What is ionic bonding

Answer 1

The electrostatic attraction between positive and negative ions
Relatively strong attraction

Question 2

How are ionic compounds held together

Answer 2

• in a giant lattice
• electrostatic attraction between positive and negative ions hold the structure together

Question 3

Properties of ionic substances

Answer 3

• high melting and boiling point
• do not conduct electricity when solid (ions in fixed positions)
• conduct when molten or dissolved in water - ions are free to move

Question 4

How are ionic compounds formed

Answer 4

Reaction of a metal and nonmetal
- electron transfer occurs

Question 5

What is a covalent bond

Answer 5

Covalent bond is a shared pair of electrons between two atoms

Question 6

What is the structure of simple molecular covalent substances

Answer 6

• do not conduct electricity
• small molecules
• weak intermolecular forces
• low melting and boiling points

Question 7

What are polymers
What are Thermosoftening polymers

Answer 7

• are very large molecules
• special types of polymers, they melt/soften when heated. This is due to strong intermolecular forces ensure that the structure is solid at room temperature.

Question 8

What are giant covalent substances

Answer 8

• solids, atoms covalently bonded together in a giant lattice
• high melting/ boiling points
• don’t conduct as there are no delocalised electrons
• diamond, graphite, silicon dioxide

Question 9

Name five allotropes of carbon and their properties

Answer 9

Diamond
- 4 covalent bonds
- very hard to + hmp
- doesn’t conduct
Graphite
- 3 covalent bonds for each carbon atom
- layers of hexagonal rings
- hmp + can conduct
- can conduct + slide over each other
Fullerenes
- hollow shaped molecules
- based on hexagonal rings
- c60 has spherical shape, simple molecular structure (Buckminsterfullerene)
Nanotube
- cylindrical fullerene
- conducts + high tensile strength
Graphene
- single layer of graphite