Metals

Question 1

Physical properties

Answer 1

Shiny
Good conductors of heat/electricity
High density
Malleable and ductile
Usually solid at room temperature
Sonorous

Question 2

Chemical properties

Answer 2

Metal + Acid = Salt + Hydrogen

Metal + Oxygen = Metal Oxide

Metal + Cold water = Metal hydroxide + hydrogen

Metal + Steam = Metal oxide + Hydrogen

Question 3

Alloys

Answer 3

Allot is a mixture of two or more metals, or a non-metal.

Alloys can be made to be harder and more resistant to corrosion.

Alloys are harder than pure metals because the presence of different sized atoms will make the layers less mobile and prevent them from slipping.

Question 4

Examples of Alloys

Answer 4

Brass: mixture of zinc and copper
Mild steel: Iron and up to 0.3% carbon
Stainless steel: Iron, nickel, chromium

Question 5

Zinc extraction

Answer 5

The ore is zinc blende (ZnS)

This is roasted in the air to form the oxide

The oxide is heated with carbon in a furnace, where it is reduced to zinc

Zinc distills out of the furnace

Question 6

Iron extraction

Answer 6

The ore is called haematite

Haematite, coke (carbon), and limestone are added to a furnace

Carbon dioxide is formed
From reaction between coke and oxygen

From decomposition of limestone

Carbon dioxide gets reduced to carbon monoxide

Carbon monoxide reduces the iron (III) oxide to iron

The impurity in the ore is sand (silivon IV oxide)
This reacts with calcium oxide to form slag

Molten slag floats on molten iron
This can be run off separately and used as building material

Question 7

Uses of metal

Answer 7

Aluminium
- Aircraft manufacture due to strength and low density
- Food contains due to corrosion resistance

Zinc
- Galvanizing and brass making

Copper
- Electrical wiring and utensils

Steel
- Car bodies and machinery
- Stainless steel