quiz 9

Question 1

Explain why does diamond does not conduct electricity

Answer 1

The atoms dont have an overall charge
it doesnt have delocalised electrons
so charges cant flow

Question 2

Explain how graphite conducts electricity. make full reference to its structure and its bonding

Answer 2

Each carbon has 3 bonds only
There is therefore one delocalised electron per carbon atom
The delocalised electrons are free to move and carry charge through the graphite

Question 3

Give 3 examples of substances with a giant covalent structure

Answer 3

diamond,graphite and silicon dioxide

Question 4

Explain why polymers have high melting points relative to substances made of small molecules

Answer 4

They have much larger molecules
so stronger intermolecular forces
which require more energy to overcome

Question 5

Describe the structure of graphite

Answer 5

Each carbon atoms forms 3 covalent bonds with 3 other carbon atoms
The atoms form layers made of hexagonal rings

Question 6

Name the type of substances that form covalent bonds when they react together

Answer 6

Non-metals

Question 7

EXplain why graphite can act as a lubricant

Answer 7

There are no covalent bonds between the layers
so they are free to slide over each other

Question 8

Describe the structure of substances containing small molecules

Answer 8

small molecules made up of atoms held together by strong covalent bonds
weak intermolecular forces act between molecules