Question

Give reason.
Petroleum is referred to as “black gold”.

Answer 1

The term “black gold” is used with reference to petroleum and its various derivatives. The word “black” refers to the colour of petroleum in its crude form. The word “gold” implies that petroleum and all the various products of petroleum (like diesel, petrol, kerosene, wax, plastics and lubricants) are as valuable to human society as the metal gold.