Carbon Dioxide is an unreactive, colourless, odourless gas that occurs in small quantities in the earth's atmosphere naturally. The earth's ocean, soil, plants and animals release CO2. The formula of Carbon Dioxide is CO2. The CO2 molecule contains 2 oxygen atoms that each share 2 electrons with a carbon atom to form 2 carbon - oxygen double bonds. The atoms are arranged as so (OHT). This is called a 'linear molecule'. Carbon dioxide is commonly found as a gas and is never a liquid. It sublimes to a solid known as 'dry ice' which is used as a substitute for normal ice as it is a lot colder and doesn't melt. Humans and animals breathe out Carbon