Coal is made largely of carbon but also features other elements such as hydrogen, oxygen, sulfur and nitrogen.
Coal starts off as plant matter at the bottom of water. It is eventually covered and deeply buried by sediments where over time metamorphosis (a change in form) takes place.
Different types of coal contain different amounts of carbon. Lignite contains only around 60 to 75%, while anthracite contains more than 92%.
Anthracite is a hard, shiny, black coal that burns with a blue, smokeless flame. While most forms of coal are associated with sedimentary rock, anthracite undergoes metamorphism and is linked to metamorphic rocks.
Coal has long been burned to create electricity and heat. The use of coal is increasing every year, in 2006 the world consumed over 6,000,000,000,000 kilograms of coal!
Coal is the world’s largest source of energy for the production of electricity.
Coal is converted to electricity by being burned in a furnace with a boiler. The boiler water is heated until it becomes steam, with the steam then spinning turbines and generators to create the electricity.
Nearly 70% of China’s electricity comes from coal. In total, coal produces around 40% of the world’s electricity.
Coal mining and the subsequent burning of coal can have many bad effects on both humans and the environment. Examples of this include waste products, acid rain, contaminated water, poisonous emissions, high levels of carbon dioxide and increased risks of lung cancer for coal plant workers.
A popular saying among many cultures is that if you behave badly during the year, Santa will deliver you a lump of coal for Christmas.
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