(a)[1]
State the volume percentages of nitrogen and oxygen found in dry air. nitrogen ............ % oxygen ............ %
(b(i))[1]
Draw a ‘dot-and-cross’ diagram for an oxygen molecule. Include only the outer-shell electrons.
(b(ii))[1]
State the formula for argon gas.
(c)[2]
Titanium is obtained from titanium(IV) chloride by reduction with molten sodium in an argon atmosphere rather than in air. Suggest why this reaction is done in an argon atmosphere and not in air.
(d)[1]
State one further use of argon.