Metals, alloys and allotropes

Question 1

Why are metals conductive?

Answer 1

When metals bond their electrons are delocalised forming a sea of delocalised electrons that are free to move through the whole structure and are charge carriers

Question 2

Why do metals have high boiling points?

Answer 2

They are giant structures with lots of bonds so a lot of thermal energy is required to break these bonds.

Question 3

Why can metals be bent?

Answer 3

The layers in a metal can slide over one another.

Question 4

What is an allotrope?

Answer 4

Two or more physical forms of which an element can exist in.

Question 5

List 5 allotropes of carbon

Answer 5

Diamond, (Buckminster) fullerenes, Graphite, Graphene, Carbon nanotubes

Question 6

Diamond

Answer 6

Each carbon forms four bonds with other carbon atoms. It is very hard, not conductive, high melting and boiling points. It is used in jewellery and diamond tipped tools.

Question 7

Fullerenes

Answer 7

Large molecules, 60 carbon atoms. They are strong, light, slippery and can withstand pressure. Used in drug delivery and as a lubricant to strengthen materials.

Question 8

Graphite

Answer 8

Unusually forms 3 bonds, 1 electron delocalises, weak forces between layers. Soft, layers can slide, conducts electricity. It is used in pencils, lubricants and electrodes.