Covalent Bonding

Question 1

What is covalent bonding?

Answer 1

When non-metal atoms bond together by sharing pairs of electrons to form covalent bonds

Question 2

Give the 4 main features of covalent bonding.

Answer 2

1. Strong b/c the positive nuclei of bonded atoms are attracted to the shared pair(s) of electrons by electrostatic forces.
2. Each atom makes enough covalent bonds to fill up its outer shell, creating stability.
3. Electrons are only shared in the outermost shell.
4. Covalent bonds arrange themselves so they’re as far apart as possible.

Question 3

Give the advantages and disadvantages of 3D representations of covalent bonds.

Answer 3

Advantages:
1. Show the atoms, the covalent bonds, and their arrangement in space.

Disadvantages:

1. Can be confusing for large molecules
2. Doesn’t show which atoms the electrons come from
3. Suggests there are gaps between atoms - this is where the shared electrons are.

Question 4

Give the advantages and disadvantages of 2D representations of covalent bonds.

Answer 4

Advantages:

1. Shows electrons and which atoms they come from
2. Shows how atoms are connected in large molecules (Displayed formula - DF)

Disadvantages:

1. Don’t show the relative size of the atoms and how they are arranged in space (DC)
2. Doesn’t show the 3D structure of the molecule

Question 5

Give the main features of simple covalent structures.

Answer 5

1. Intermolecular forces are very weak
2. Low mp and bp b/c the molecules are easily separated from each other, as you only have to overcome the weak intermolecular forces and not the actual bonds.
3. Bigger molecules have stronger intermolecular forces
4. Do not conduct electricity b/c they are not charged, so there are no delocalised electrons or ions.