Metals Test

Question 1

Compared to non-metals, metals are:

a) good conductors of heat but not electricity
b) good conductors of electricity but not heat
c) good conductors of both heat and electricity
d) not good conductors

Answer 1

c) good conductors of both heat and electricity

Question 2

Which list is correct if these metals are put in order of their reactivity with water, starting with the most reactive first?

a) sodium, potassium, magnesium, silver, copper
b) potassium, sodium, copper, magnesium, silver
c) sodium, potassium, magnesium, copper, silver
d) potassium, sodium, magnesium, copper, silver

Answer 2

d) potassium, sodium, magnesium, copper, silver

Question 3

Which of the following is the correct way to test for hydrogen gas?

a) Bubble the gas through limewater
b) Bubble the gas through universal indicator solution
c) Put a glowing splint into a tube of the gas (the splint will burn brightly)
d) Put a burning splint into a tube of the gas (the gas will explode with a squeaky pop)

Answer 3

d) Put a burning splint into a tube of the gas (the gas will explode with a squeaky pop)

Question 4

Which statement is FALSE?

a) an alloy of aluminium is used to make planes because it has a low density
b) sliver is used to make jewellery because it is in-reactive
c) lead is used to make fishing weights because it has a high density
d) copper is used to make electrical wires because it conducts heat well

Answer 4

d) copper is used to make electrical wires because it conducts heat well

Question 5

Which statement is FALSE?

a) a mixture of metals is called an alloy
b) bronze is an alloy of copper and tin
c) solder is an alloy with a very high melting point
d) carbon is added to iron to make steel

Answer 5

c) solder is an alloy with a very high melting point

Question 6

Which statement is TRUE?

a) metals should be recycled because we have an unlimited supply of them
b) iron is extracted from its ore by heating with carbon in blast furnace
c) aluminium is extracted from its ore by electrolysis because it is un-reactive
d) reactive metals form reactive compounds

Answer 6

d) Iron is extracted from its ore in blast furnace with carbon

Question 7

Copper is more reactive than silver. Iron is more reactive than copper. This means:

a) copper will react with iron nitrate solution
b) silver will react with iron nitrate solution
c) iron will react with silver nitrate solution
d) silver will react with copper nitrate solution

Answer 7

c) iron will react with silver nitrate solution

Question 8

Choose the correct products to complete the word equation: zinc + sulfuric acid ->

a) zinc + sulfur + acid
b) zinc hydrate + sulfur
c) zinc sulfate + hydrogen
d) zinc hydroxide + hydrogen

Answer 8

c) zinc sulfate + hydrogen

Question 9

When an iron nail is left outside to rust, what happens to it?

a) its mass increases
b) it dissolves
c) its mass decreases
d) its mass stays the same, it just changes colour

Answer 9

a) its mass increases

Question 10

Which of the following would definitely NOT protect an iron object from corrosion?

a) painting it
b) attaching it to a strip of tin
c) attaching it to a strip of magnesium
d) covering it in grease

Answer 10

b) attaching it to a strip of tin

Question 11

Read:
Objects made of COPPER are often black when they are found.
GOLD objects are still shiny and in very good condition.
Objects made from IRON are usually badly corroded and are mainly rust.
They never find any objects made of MAGNESIUM.

Which of the four metals mentioned is the least reactive?

Answer 11

Gold

Question 12

Which f the following statements is TRUE?

a) Gold is more reactive than copper
b) Iron is less reactive than copper
c) Iron is more reactive than gold
d) Copper is less reactive than gold

Answer 12

c) Iron is more reactive than gold

Question 13

Which compound could be the black coating that forms on the surface of copper?

Answer 13

Copper Oxide

Question 14

Iron objects coated with paint have not rusted very much. Why is this?

Answer 14

Iron is protected by the paint using physical protecting which prevents contact between steel and (oxygen + water)

Question 15

Read:
Objects made of COPPER are often black when they are found.
GOLD objects are still shiny and in very good condition.
Objects made from IRON are usually badly corroded and are mainly rust.
They never find any objects made of MAGNESIUM.

Explain why archaeologists never find any objects that are made of magnesium when they dig up ancient remains.

Answer 15

Magnesium is very reactive so it will be combined with oxygen or other elements.

Question 16

Give two substances which are needed for the steel to rust.

Answer 16

Water and oxygen

Question 17

Steel objects coated with tar have not rusted very much. Why is this?

Answer 17

The steel is protected using physical protection which prevents contact between steel and oxygen and (oxygen + water)

Question 18

How else could steel objects be protected from rusting?

Answer 18

Painting, coating in plastic, galvanising, tin plating.

Question 19

John suggests that an iron bucket could be protected by coating it in tin.
Helen says coating it in zinc would be better.

Explain, using your knowledge of chemistry, which pupil is correct?

Answer 19

Helen is correct because a tin coating only provides physical protection. If it is scratched, the steel will rust more quickly because iron is higher in the reactivity series. A zinc coating will provide physical protection when intact, but if scratched will still protect the steel sacrificially because zinc is above iron in the reactivity series.