Most of it is from the trees of the great forests of 200 million years ago.
coal is found underground - and is formed by buried forests and vegetable matter being compressed over millions of years
Not sure if this will answer your question, but I'll give it a shot. It's less about the fact that is is coal and more about the fact that coal gives off heat. When coal was first being used as a heat source, it was cheaper than wood and there was a lot of it. So really the origin of the energy is in the heat that the coal generates when on fire and less about the coal itself.
how has coal mining changed over time
Zheng He was the one who had coal. He and his father, the emperor of China, and his uncle ,Samuel had created coal together on a farm in China.
Coal is not an invention, but rather the natural result of the fossilization of plants from the Carboniferous period.
coal is not renewable because coal is hot.
does it come from the Huntly coal fields, or is it imported from overseas.
coal and oil come from many different places. Like coal from mines. oil from the ground.
yes
silver and coal
yes
there is not a certain size a coal rock can be because they come in all sizes.
Coal
Mines
Coal.
From prehistoric plants that died and turned to coal. Sometimes in underground coal mines we find a tree stump that is coal, but can still be recognized as a tree stump.
Petrochemicals come from petroleum -Oil. However, some chemicals extracted from petroleum (petrochemicals) , may also be extracted form coal.