C3

Question 1

what are giant covalent bonds always solid at room temp?

Answer 1

-because the have high meting and boiling points.

Question 2

describe and explain the properties of allotropes of carbon?

Answer 2

diamond-
four strong covalent bonds for each carbon atom
- very hard ( strong bonds)
- very high melting point( strong bonds)
-does not conduct ( no delocalised electrons as all outer electrons are in covalent bonds)
- shape is tetrahedral

Question 3

describe and explain the properties of allotropes of carbon?

Answer 3

graphite-
- three covalent bonds for each carbon atom
- layers of hexagonal rings
- high melting point
- layers free to slide as they have weak intermolecular forces can be used as lubricants in machines.
conduct thermal and electricity due to one delocalised per each carbon atom.

Question 4

silicon dioxide

Answer 4

-very high melting and boiling points
- they are insoluble in water
- they are hard and do not conduct electricity

Question 5

fullerenes

Answer 5

• hollow shaped molecules
  -high tensile strength
• high electrical conductivity and high thermal conductivity.

Question 6

graphene

Answer 6

• a single layer of graphite.
• most reactive form of carbon
  -most reactive form of carbon
  -low density