Aluminium powder is used in thermite welding because :

1. it is strong reducing agent
2. it is strong oxidizing agent
3. it is corrosion resistant
4. it is a good conductor of heat.

Select which is not an alloy of copper :

1. Brass
2. Bronze
3. Solder
4. Duralumin.

Name the following :

(i) The property possessed by metals by which they can be beaten into sheets.

(ii) A compound added to lower the fusion temperature of electrolytic bath in the extraction of aluminium.

(iii) The ore of zinc containing its sulphide.

Heating an ore in a limited supply of air or in the absence of air at a temperature just below it's melting point is known as :

1. Smelting
2. Ore dressing
3. Calcination
4. Bessemerisation