List two non-living (abiotic) forms of carbon in the cycle and give the chemical formula of each.

Two abiotic forms of carbon are CARBON DIOXIDE AND METHANE.
The element carbon is continuously been recycled in nature. The abiotic components of the carbon cycle refers to the non living part of the carbon cycle which has influence on the living part. Methane is a type of fossil fuel whose major component is carbon.
The chemical formula of carbon dioxide is CO2 while that of methane is CH4.