Question

carbon is found in the atmosphere in the form of
carbohydrates
calcium carbonate (caco₃)
carbon dioxide (co₂)
ammonia (nh₃)

Explanation:

Carbon in the atmosphere exists mainly as carbon - dioxide. Carbohydrates are organic compounds in living organisms. Calcium carbonate is a solid compound found in rocks and shells. Ammonia contains nitrogen and hydrogen and not carbon as the main constituent in relation to the atmosphere's carbon forms.

Answer:

carbon dioxide ($CO_2$)