What is coal and how was it formed?

Answer 1

Coal is a nonrenewable hard black rock-like substance which is burned to heat houses and produce electricity and was once used to power trains and boats. It is made up of: carbon, hydrogen, oxygen, nitrogen and varying amounts of sulphur.

When the geologists examine the fossil plants in coal, they find the leaves and bark came from plants which no longer exist on earth. They infer that these plants probably grew in moist warm swampy forests roughly 300 million years ago. Over a period of time the plants in these forests died, leaving layers of decaying wood and other plant material. As more and more sediments were deposited the weight of these layers forced out much of the water and gases from the plant material, making it richer in carbon. Thus began the slow change over millions of years from wood to coal.

Answer 2

Coal is a combustible sedimentary rock formed from decayed plant matter over millions of years. It undergoes a process called coalification, where the plant material is exposed to high pressure and heat, eventually transforming into coal.