Answer:
Carbon atoms are found in atmosphere naturally. The burning of fossil fuels or volcanic eruptions mainly give reason to their existence. Plants take in CO2 during photosynthesis, which in turn forms glucose C6H12O6. This product is then passed on to animals through plants as food. This carbohydrate is then used up by animals during the process known as respiration, releasing CO2 once again into the air. CO2 is also absorbed by carbon sinks such as forests and oceans.
Step-by-step explanation: