One carbon atom and two oxygen atoms make up carbon dioxide, a chemical compound.
The formula is often used to refer to it.
Carbon dioxide is a chemical element that can be found in the atmosphere.
At room temperature, it is a gas.
Discovery of carbon dioxide:
has been present in the atmosphere since the Earth condensed from a ball of hot gases following its formation from the explosion of a huge star about five billion years ago.
At that time the atmosphere was mainly composed of nitrogen, and water vapor, which seeped through cracks in the solid surface.
A very similar composition emerges from volcanic eruptions today.
As the planet cooled further some of the water vapor condensed out to form oceans and they dissolved a portion of the but it was still present in the atmosphere in large amounts.