Covalent Bonding

Question 1

What are covalent bonds?

Answer 1

Electrons are shared between non-metal atoms. The number of electrons shared depends on how many extra electrons the atoms need to achieve a full outer shell.

Question 2

Single Bonding

Answer 2

Each atom shares one pair of electrons.

Question 3

Double Bonding

Answer 3

Each atom shares two pairs of electrons.

Question 4

Covalent Structures

Answer 4

Depending on the number of atoms and how they are bonded, different covalent structure can be formed.

1. Giant Covalent Structures
2. Simple Molecules
3. Large Molecules

Question 5

Diamond

Answer 5

Giant Covalent Structure - carbon allotrope

• Hard, 3D structure, shiny
• Poor conductor of electricity.
• Used on drill heads due to hard nature.
• High melting point.
• Very strong covalent bonds so requires a lot of energy to
  break them (four bonds each atom)

Question 6

Graphite

Answer 6

Giant Covalent Structure - carbon allotrope

• Soft, arranged in layers, slippery
• Used in pencils and lubricants
• The fourth electron in carbon exists between the layers
  and is mobile, thus graphite conducts electricity.
• Weak forces between layers, so doesn’t require a lot of
  energy to break them.
• Each carbon atom makes three covalent bonds.

Question 7

Simple Molecule: Water

Answer 7

Contains few atoms with strong covalent bonds between the atoms themselves. The molecules that are different are held together by weak intermolecular forces.

Low melting and boiling points, only the weak intermolecular forces have to be overcome to melt or boil the substance.

Question 8

Large Molecule: Polymers

Answer 8

Many repeating units joined by covalent bonds.
Seperate chains are held together by intermolecular forces.