Question

(2) Petroleum is called 'black gold",​

Answer 1

Explanation:

The Petroleum is called black gold because when the crude oil is extracted from the soil below, it is black in colour. Petroleum is very expensive like gold. Comparing its high value with gold in terms of properties and moneywise; it is regarded as black gold. Many components of crude oil have commercial importance

Answer 2

because it's black in colour ( black)and it's very expensive (gold)... that's why black gold..

Explanation:

I hope it's help u....