Covalent Bonding

Question 1

What 2 forces occur in a covalently bonded pair?

Answer 1

• electrostatic attraction between the positive nuclei and negative electrons
• repulsion between the positive nuclei
  (To maintain the covalent bond, there must be balance between these forces)

Question 2

What are the 3 typical properties of molecular substances?

Answer 2

• fairly low melting/boiling points so usually liquids/gases at standard temp and pressure
• they don’t conduct electricity because there are no charge carriers that are free to move
• they are usually insoluble in water (or only slightly soluble) because the polar water molecules are more attracted to each other than the molecular substance

Question 3

What is dative covalent bonding?

Answer 3

Bonding where both electrons is donated by one atom

Question 4

Which compound has an atom with less than 8 electrons in its outer shell?

Answer 4

Boron in boron trifluoride

Question 5

Which compound’s atoms use d orbitals to ‘expand the octet’ (has more than 8 electrons in their outer shell)?

Answer 5

The sulfur in sulfur hexafluoride (S has 12 e in outer shell)