(a)- Platinum, gold, and silver are highly lustrous metals and resistant to corrosion. They are unreactive metals that do not tarnish easily. They are highly malleable metal that can be transformed into any shapes or designs. That is why platinum, gold, and silver are used to make jewellery.

(b)- Sodium, potassium and lithium are highly reactive metal that catches fire vigorously when kept in the air. That is why they are always stored in kerosene oil.

(c)- Aluminium is a reactive metal that can react with oxygen to form a thin layer of oxide over its surface. This is a stable layer that prevents the reaction of other substance with the metal underneath it. This layer also prevents the corrosion of the metal. It is a malleable substance that is a good conductor of heat and can available easily. That is why aluminium is used to make utensils for cooking.

(d)- Carbonate and sulphide ores are converted into oxides during the process of extraction because it is easier to extract metal from its oxide than its sulphides or carbonates.