Process in which some minerals are converted to the oxide by heating in the air at a temperature below their melting point is called

The boiling point of diesel is

A. 270 °C to 340 °C

B. 350 °C to 500 °C

C. 500 °C to 600 °C

D. more than 500 °C

The boiling point of petrol is

A. below 20 °C

B. 35 °C to 70 °C

C. 70 °C to 120 °C

D. 170 °C to 250 °C

Process in which metal ions are reduced to free metals is called

A. roasting

B. smelting

C. Bessemerization

D. concentration

Ore of iron is called

A. hematite

B. chalcopyrite

C. bauxite

D. halite

Ore of silicon is called

A. galena

B. zinc blende

C. Cassiterite

D. silica