5.3 : Covalent Bonding

Question 1

Define covalent bonding

Answer 1

The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms.

Question 2

Where does covalent bonding occur?

Answer 2

Between :

Non-metallic elements (H2, O2)
Compounds of non metallic elements ( H2o, CO2)
Polyatomic ions ( NH4+ )

Question 3

Explain covalent bonding in terms of orbitals

Answer 3

It is the overlap of atomic orbitals, each containing one electron.

Doesn’t necessarily have noble gas structure.

Question 4

Are covalent bonds localised or delocalised?

Answer 4

Localised : acts solely between the shared pair of electrons and the nuclei of the two bonded atoms.

Question 5

What are lone pairs?

Answer 5

Electron pairs that are not bonded

Question 6

What is a double covalent bond?

Answer 6

The electrostatic attraction is between two shared pairs of electrons and the nuclei of the bonding atoms.

Has noble gas structure.

Question 7

What is a triple covalent bond?

Answer 7

The electrostatic attraction is between three shared pairs of electrons and the nuclei of the bonded atoms.

Has noble gas structure.

Question 8

What is a dative covalent bond?

Answer 8

Also called a coordinate bond.

The shared pair of electrons has been supplied by one of the bonded atoms only.

Question 9

How does average bond enthalpy relate to covalent bonds?

Answer 9

The larger the average bond enthalpy, the stronger the covalent bond.