| C2 |
symbol of the chemical element carbon. |
| carbohydrate |
a compound made of carbon, hydrogen, and oxygen. It is formed mainly by plants, and it is used in the body to easily produce and store energy. Sugars and starches are carbohydrates. [2 definitions] |
| carbon |
a chemical element found in all living things. Pure carbon occurs as diamond or graphite. It is also often found in compounds with other elements. (symbol: C) |
| carbon dioxide |
a gas without color or odor that is made up of carbon and oxygen. Carbon dioxide is in the air and is used in soft drinks. Frozen carbon dioxide is called dry ice. |
| carbon monoxide |
a poisonous gas with no color or smell. Carbon monoxide forms when a material made of carbon, like gasoline, is not fully burned because of too little air. |
| cast iron |
a mixture of iron and carbon, with other materials added to make it either hard and brittle or soft and strong. |
| charcoal |
the solid, black form of carbon made by burning wood or other matter in a space with very little oxygen. [1/2 definitions] |
| climate change |
a major change in Earth's climate that is of current concern and which is associated with an increase in carbon dioxide and certain other gases in Earth's atmosphere. These gases contribute to the increasing temperature of the planet. [1/2 definitions] |
| coke |
the carbon substance that is left after coal has been heated without air. Coke is used as a fuel for doing certain kinds of work in a factory. |
| diamond |
a clear mineral that is a crystal form of pure carbon. Diamonds are the hardest natural substance known. They are used in making jewelry and as tools for cutting hard materials. [1/5 definitions] |
| fat |
a white or yellow oily substance found in some parts of animals or plants. Fat is made of carbon, hydrogen, and oxygen. [1/4 definitions] |
| fossil fuel |
any carbon-containing fuel formed from the remains of prehistoric plants and animals. Coal, petroleum, and natural gas are examples of fossil fuels. |
| graphite |
a soft black or gray form of carbon. It is the writing material in pencils, and it has many uses in industry. |
| greenhouse effect |
the warming of the earth's surface that takes place when heat from the sun is held in by the earth's atmosphere. The greenhouse effect can be caused by too much carbon dioxide being released into the air from the burning of fossil fuels. |
| iron |
any alloy of iron with carbon and other elements which can be used to make a variety of tools, containers, and other objects. [1/9 definitions] |
| limestone |
a rock formed mostly from shells and other animal remains. Limestone is used in building and in making cement, lime, and carbon dioxide. |
| lung |
one of two organs in the chest that are used in breathing. Lungs are found in mammals, birds, reptiles, and some other animals. They bring oxygen to the body and get rid of carbon dioxide. |
| methane |
a gas made of carbon and hydrogen atoms that is stored in and collected from the earth. Methane is used for heating and cooking in the form of natural gas. |
| photosynthesis |
the process by which a green plant uses sunlight to change water and carbon dioxide into food for itself. |
| protein |
a substance that is made up of nitrogen, carbon, oxygen, hydrogen, and possibly other elements. Proteins are found in all living things and are a necessary part of life processes. |
| soda |
a drink made with a sweet flavoring and water that contains carbon dioxide. [2/3 definitions] |