Give
reasons
(a) Platinum,
gold and silver are used to make jewellery.
(b) Sodium,
potassium and lithium are stored under oil.
(c) Aluminium is a highly reactive metal, yet it is used to make
utensils for cooking.
(d) Carbonate and sulphide ores are usually converted into oxides
during the process of extraction.
Give reasons
(a) Platinum, gold and silver are used to make jewellery.
(b) Sodium, potassium and lithium are stored under oil.
(c) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
(d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction.
(a) Platinum, gold, and silver are used to make
jewellery because they are very lustrous.
Also, they are very less reactive and do not corrode easily.
(b) Sodium, potassium, and lithium are very
reactive metals and react very vigorously with air as well as water.
Therefore, they are kept immersed in kerosene oil in order to prevent
their contact with air and moisture.
(c) Though aluminium is a highly reactive metal,
it is resistant to corrosion. This is because aluminium reacts with
oxygen present in air to form a thin layer of aluminium oxide. This
oxide layer is very stable and prevents further reaction of aluminium
with oxygen. Also, it is light in weight and a good conductor of
heat. Hence, it is used to make cooking utensils.
(d) Carbonate and sulphide ores are usually
converted into oxides during the process of extraction because metals
can be easily extracted from their oxides rather than from their
carbonates and sulphides.
(a) Platinum, gold, and silver are used to make jewellery because they are very lustrous. Also, they are very less reactive and do not corrode easily.
(b) Sodium, potassium, and lithium are very reactive metals and react very vigorously with air as well as water. Therefore, they are kept immersed in kerosene oil in order to prevent their contact with air and moisture.
(c) Though aluminium is a highly reactive metal, it is resistant to corrosion. This is because aluminium reacts with oxygen present in air to form a thin layer of aluminium oxide. This oxide layer is very stable and prevents further reaction of aluminium with oxygen. Also, it is light in weight and a good conductor of heat. Hence, it is used to make cooking utensils.
(d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction because metals can be easily extracted from their oxides rather than from their carbonates and sulphides.
