Question

Coal is formed from the remains of:
A) Vegetation only
B) Animals only
C) Both vegetation and animals
D) Neither vegetation nor animals

Answer 1

The coal formed over a period of hundreds of years. The coal has carbon as its main
constituent. One can think about the given options and their capacity to form coal and choose the
correct option.

Complete step by step answer:

1. First of all we will learn about how the coal is formed with each step. The formation of coal happened millions of years ago when the earth was full of huge animals and huge swampy forests.
2. As the huge animals and plants grew some of them died and fell into the waters and land. The plants which fell into the water later grew up in the water and their number increased further.
3. After some time there was a thick layer of dead plants and animals which was rotting in the swamp. The structure of the land on earth changed and the remains of dead animals and plants got buried very deep, stopping the decaying process.
4. There were many plants and animals which were buried periodically forming separate layers. As the millions of years had passed many layers had formed in the ground one on top of the other.
5. The heat and pressure in the buried layer produced chemical and physical changes that eliminated oxygen and left with only rich carbon deposits. And after some time the materials that had been plants and animals turned into coal.
   Therefore, option C is the correct choice.

Note:
The coal is a black colored sedimentary rock which is combustible. The coal has mostly the carbon element as its major component with some amounts of other elements such as hydrogen, nitrogen, oxygen, and sulfur. This was used as a primary source of fuel over many recent years.