C2.3 Properties Of Materials

Question 1

What element is diamond, graphite, graphene, and fullerene made from?

Answer 1

Different forms of carbon

Question 2

What is an allotrope? Give an example.

Answer 2

different forms of an element in the same state but with different atomic arrangements.

Diamond and graphite are two allotropes of carbon.

Question 3

Why do diamonds not conduct electricity?

Answer 3

Diamond has no delocalised electrons so it does not conduct electricity

Question 4

How many bonds can a carbon atom make?

Answer 4

4

Question 5

State Key facts about diamond and graphite

Answer 5

Diamond Graphite

high melting point high melting point
does not conduct electricity. conducts electricity
Strong soft
insoluble in water insoluble in water

Question 6

How many bonds are connected to graphite and diamonds?

Answer 6

Graphite:

Each carbon atom is bonded into its layer with three strong covalent bonds

Diamond:

Every atom in a diamond is bonded to its neighbours by four strong covalent bonds, leaving no free electrons and do ions

Question 7

What can graphite be used as?

Answer 7

Can be used as a lubricant as the layers slide over each other

Question 8

What happens when a substance changes state?

Answer 8

Forces of attraction between its particles are overcome.In other words, some or all of the bonds between its particles break

Question 9

How do bonds break?

Answer 9

Some bonds break going from the solid to the liquid state

all remaining bonds break going from the liquid to the gas state

Question 10

How do bonds form?

Answer 10

When a substance condenses or freezes.

Some bonds form going from the gas to the liquid state
Many bonds form going from the liquid to the solid state.

Question 11

What is sublimation?

Answer 11

Some substances can sublime-change directly from the solid to the gas state below their melting and boiling points.Iodine is like this.

Question 12

What does malleable mean?

Answer 12

(Of a metal or other material) able to be hammered or pressed into shape without breaking or cracking

Question 13

How are simple molecules and polymer molecules attracted to each other?

Answer 13

They are attracted to each other by weak intermolecular forces.

Question 14

How can a substance conduct electricity?

Answer 14

If it has charged particles that are free to move

Question 15

Why do metals conduct electricity in the solid and liquid state?

Answer 15

Because their delocalised electrons are free to move through the lattice

Question 16

Why do simple molecules, most polymers and substances with a giant covalent structure not conduct electricity?

Answer 16

Because they have no delocalised electrons