Topic 10 - Covalent Bonding

Question 1

Define covalent bonding

Answer 1

The Attaction between the nuclei of atoms and the shared pair of electrons between them

Question 2

Describe and explain the boiling points of simple molecular substances

Answer 2

Low

Because the forced between molecules are weak, and therefore not much energy is needed to overcome them

Question 3

Why do simple molecular substances not conduct?

Answer 3

Their molecules are neutral

Question 4

Describe diamond

Answer 4

• very hard -> every C has 4 strong covalent bonds
• high melting, boiling and subliming points -> giant lattice with lots of strong covalent bonds
• used for cutting

Question 5

Describe graphite

Answer 5

• anisotropic
• it can conduct, because it has delocalised electrons
• high melting, boiling and subliming point
• used as a solid lubricant because it is soft (weak intermolecular forces can slide)
• hexagonal layers -> each C has 3 bonds

Question 6

Describe C60 Fullerene

Answer 6

• Simple molecular substance
• Hollow spheres made up of 60 carbon atoms -> made up of large covalent molecules
• soft because of intermolecular forces
• Poor conductor -> the delocalised electrons can’t move between molecules