Explain the following.
(i) Aluminium alloys are used to make aircraft body.
(ii) Aluminium utensils should not be kept in water overnight.
(iii) Aluminium wire is used to make transmission cables.
(i) Aluminium alloys such as duralumin is light, tough and resistant to corrosion and hence, it is used in making aircraft body.
(ii) Because aluminium reacts with water and oxygen (dissolved in) to form a thin layer of toxic aluminium oxide on the surface of utensils.
(iii) Aluminium possesses high electrical conductivity. Therefore, it is used in making transmission cables. Further on weight to weight basis conductivity of aluminium is twice as Cu.