Question

. Give reasons: 3 marks

(a)

Gold and silver are used to make Jewellery.

(b)

Sodium and Potassium are stored under oil.

(c)

Aluminium is highly reactive, yet it is used to make utensils for

cooking.​

Answer 1

Answer: a ans]Gold and silver have the property of lustre ,which makes them shiny,so it is feasible to use them to make jewellery.

b ans]Because aluminium is malleable.

Answer 2

Explanation:

A)gold and silver are used to make jewellery because these are low reactive metals. So they rarely corrode and hence do not lose their shine and lustre.

b-

The reaction of these substances with oxygen is highly exothermic which may cause fire, also they react with water to form base so they are kept in oil.

c-

This is because aluminium is good conductor of heat and electricity. To prevent its reaction with food at high temperature a protective layer of aluminium oxide is formed which prevent further corrosion