Note: Chlorhexidine may cause staining of the tooth, tooth filling, and dentures or other mouth appliances. Tetracycline use during tooth development phases (from the last half of pregnancy through eight years of age) may cause permanent discoloration (yellow, gray, brown) of teeth.
What is Coal made of? Coal is made from trees or plants that decayed on the ground for millions of years. The remains of various plants and trees then mixed with the other components of the ground and eventually going through several natural processes making them more like solid rocks.
Many industries use coal and coal byproducts. The concrete and paper industries burn large amounts of coal to produce heat. The steel industry uses coal indirectly to make steel. Steel plants use coal that is baked in furnaces to make coal coke, and the coke is used to smelt iron ore into iron to make steel. The high temperatures created by burning coke give steel the strength and flexibility needed for bridges, buildings, and automobiles.