Metals react with oxygen, sulfuric acid, and water to form metal oxides, sulfates, and hydroxides respectively, with hydrogen gas given off as a product. Aluminum forms a protective oxide layer preventing further corrosion without needing paint, while gold does not react with air at all, and attaching copper to iron does not reduce the corrosion rate of iron which forms compounds when reacting with chemicals in its environment through oxidation and tarnishing processes.

1. metal + sulphuric acid --- metal sulphate + hydrogen.
metal + oxygen ---- metal oxide.
The gas that
reacts with
metals mostly
is oxygen.
metal + water --- metal hydroxide + hydrogen.
When Metals react
with the gas which is
given off is called
hydrogen.
Attaching a
copper rod to iron
would not reduce
the corrosion
rate.
Aluminium does
not need to be
painted because it
forms a natural
protective layer.
Gold does not
react with the
air.
When a copper
coin goes black
and dull oxidation
and tarnishing
take place.
To break
bonds
electricity
is used.
When iron
corrodes it reacts
with chemicals in
the environment
to form
compounds.