Why are coal and petroleum categorised as natural resources? Give a reason as to why they should be used judiciously.

Explanation

Coal and petroleum are obtained from nature. They are non-renewable resources which cannot be renewed within a short period of time.
Detailed Answer:
Coal and petroleum are formed from the degradation of bio-mass subjected to various biological and geological process over a million of years. Thus, cannot be manufactured by humans. Therefore, coal and petroleum are categorised as natural resource.
They should be used judiciously as they cannot be manufactured by humans and naturally it takes million of years to form.