Year 9 Reactivity

The gas in the air that reacts with metals most easily is:

• argon

• carbon dioxide

• nitrogen

• oxygen

A metal that does not react with the air is:

• calcium

• gold

• iron

• magnesium

Complete the word equation:
iron + oxygen  $\rightarrow$  

• iron sulphate

• iron oxide

• carbon dioxide

• carbon monoxide

A copper coin is shiny when it is new, but will eventually go black and dull. The two words which best describe this process are:

• oxidation and neutralisation

• corrosion and neutralisation

• corrosion and reduction

• oxidation and tarnishing

The gas which is given off when metals react with water is:

• carbon dioxide

• hydrogen

• oxygen

• nitrogen

Complete the word equation:
calcium + water  $\rightarrow$  

• calcium oxide + carbon dioxide

• calcium sulphate + oxygen

• oxygen + hydrogen

• calcium hydroxide + hydrogen

Look at these diagrams, and then choose the correct order of reactivity for metals X, Y and Z (the most reactive metal should be first).

• Z, X, Y

• Y, Z, X

• X, Y, Z

• Z, Y, X

Reactive metals such as sodium, magnesium and calcium:

• have been known since ancient times because they do not join with other elements.

• are easily extracted from their oxides by heating with carbon which makes carbon dioxide.

• are extracted from their compounds using electricity to break the bonds.

• cannot be extracted from their compounds

  because they are too reactive.

When iron corrodes:

• it evaporates into the air

• it forms a protective layer on its surface

• it reacts with chemicals in the environment to form compounds

• it turns green because it forms a coating of copper carbonate

Some window frames are made of a metal which does not need to be painted, because it forms a naturally protective layer. A metal which can be used in this way is:

• copper

• PVC

• iron

• aluminium