The Enlightenment
The Enlightenment was a historical period in the seventeenth and eighteenth centuries in E...
Carbon is a chemical element. Carbon can bond with many other elements to form compounds. There are millions of known compounds that contain carbon. Some are essential to life. Others are deadly poisons. Carbon is a major component of plastics. Carbon is also found in fuels such as coal, natural gas, and petroleum. The human body is almost one-fifth carbon. Humans exhale carbon dioxide. Carbohydrates are sugars made of carbon and hydrogen. Carbon by itself occurs in several different forms, depending on how the carbon atoms bond with each other. The hardest natural substance, the diamond, is a special form of carbon. One of the softest substances, graphite, is also carbon. Graphite is mixed with clay to form the "lead" in pencils. There are even forms of carbon where the atoms bond in a structure that resembles a soccer ball. Carbon is the basis of life as we know it on Earth.
The Enlightenment was a historical period in the seventeenth and eighteenth centuries in E...
Every seventy-five years, a bright jet of light races across the Earth's atmosphere. T...
How often do you emit a sternutation? The chances are good that you do so fairly often. &q...