Carbon dioxide is a very prevalent molecule. It is a product of respiration in humans and other animals, and green plants use carbon dioxide and water to form carbohydrates in photosynthesis. Carbon dioxide emissions, produced when any carbon-containing substance is burned, are a significant contributor to global climate change. It is also used in refrigeration and for beverage carbonation.
Anatomy of a Greenhouse Gas
The carbon dioxide molecule contains one carbon and two oxygen atoms. The molecule is linear, with the carbon atom in the center, forming a double bond with an oxygen on each side. Carbon dioxide is an odorless, colorless, nonflammable gas at room temperature. It exists as a solid at negative 78 degrees Celsius (negative 108.4 degrees Fahrenheit). In this form it is commonly known as dry ice. Carbon dioxide is water-soluble when pressure is sufficiently high. Once pressure drops, carbon dioxide will try to escape, forming bubbles that are recognizable as carbonation.