Describe how coal is formed from …

Coal was formed by the decomposition of large land plants and trees buried under the Earth about 300 million years ago.

About 300 million years ago, the Earth had dense forests in the low lying wet areas.

Due to natural calamities like earthquakes, volcanoes, floods, etc.  these forests got buried under the surface of the Earth.

As more soil got deposited on them, they were compressed.

As a result, the temperature also rose as they sank deeper and deeper.

Due to high pressure and temperature and the absence of air, the wood of the buried forest plants and trees slowly got converted into coal.

The slow process by which the dead plants buried under the Earth have become coal is called as carbonisation.

Since coal was formed from the remains of the plants, it is called a fossil fuel.

Coal, which is mainly carbon, on heating produces mainly carbon dioxide gas and a lot of heat energy.