C3.7 Giant Covalent Structures (Finished)

Question 1

In giant covalent structures how are atoms held together?

Answer 1

They are bonded to each other by strong covalent bonds

Question 2

Why do giant covalent structures have very high melting points?

Answer 2

A lot of energy is needed to break the covalent bonds between atoms

Question 3

Do giant covalent structures conduct electricity?

Answer 3

No since they don’t contain charged particles. Appart from graphite which does

Question 4

Describe the structure of diamond

Answer 4

Each carbon atom forms four covalent bonds in a very rigid giant covalent structure

Question 5

Describe the structure of graphite

Answer 5

Each carbon atom forms three covalent bonds to create two layers of hexagons. Each carbon atom also has one free electron

Question 6

What atoms is silicon dioxide made of?

Answer 6

Silicon and oxygen

Question 7

What are the properties of giant covalent structures?

Answer 7

• They have high melting and boiling points
• They are insolvable in water
• They do not conduct electricity (appart from granite)
• They are hard

Question 8

Why can you write using graphite? (Pencil)

Answer 8

There aren’t any covalent bonds between the layers of graphite, so they are held together weakly being free to move over each other. One layer will slide off and stay on paper when you write with a pencil

Question 9

Why does graphite conduct electricity and thermal energy?

Answer 9

Only three of each of carbon’s for outer electrons are in bonds so each carbon atom has one electron which is delocalised, making it free to move around and conduct energy

Question 10

What are the free electrons of graphene called?

Answer 10

Delocalised electrons