2.3 - Giant covalent structures

Question 1

How are giant covalent structures created?

Answer 1

Atoms of some elements can form several covalent bonds, which can join together in giant covalent structures, or macromolecules

Question 2

Why do giant covalent structures have such high melting points?

Answer 2

Each atom in the structure is joined to several other atoms by strong covalent bonds. It takes lots of energy to break down the lattice, so these substances have very high melting points

Question 3

What are two giant covalent structures that are forms of carbon?

Answer 3

1) Diamond

2) Graphite

Question 4

What are four properties of the structure of diamond?

Answer 4

1) It is a form of carbon
2) It has a three-dimensional giant structure
3) Each carbon atom is covalently bonded to four other carbon atoms
4) This makes it hard and transparent

Question 5

What are six properties of the structure of graphite?

Answer 5

1) It is a form of carbon
2) One electron from each carbon atom is delocalised
3) Each carbon atom is covalently bonded to three other carbon atoms
4) These form giant, flat hexagonal layers
5) There no covalent bonds between layers, and only weak intermolecular forces between them
6) This makes graphite slippery and grey

Question 6

Why can graphite conduct heat and electricity?

Answer 6

In graphite, each carbon atom is only bonded to three other carbon atoms, meaning one electron from each carbon atom is delocalised. These delocalised electrons allow carbon to conduct heat and electricity

Question 7

What are four properties of the structure of fullerenes?

Answer 7

1) It is a form of carbon
2) They are large molecules formed from hexagonal rings of carbon atoms
3) The rings join together to form cage-like shapes with different numbers of carbon atoms
4) Some of these are nano-sized

Question 8

What are four applications scientists have found for fullerenes?

Answer 8

1) Drug delivery into the body
2) Lubricants
3) Catalysts
4) Reinforcing metals