Which element essential for plant growth is derived from atmospheric CO2?

Carbon is the essential element for plant growth that is derived from atmospheric CO2. Plants utilize carbon dioxide during the process of photosynthesis, where they convert CO2 into glucose and other organic compounds that are critical for their growth and development. This process not only allows plants to create their own food but also contributes to the release of oxygen into the atmosphere, which is essential for the survival of aerobic organisms.

While oxygen and hydrogen are important for plants, they are not sourced directly from atmospheric CO2. Oxygen, for instance, is released as a byproduct of photosynthesis but originates from water molecules split during the process. Hydrogen, on the other hand, comes mainly from water (H2O), which plants absorb from the soil. Nitrogen is another crucial nutrient for plants, mainly obtained from the soil; it is not derived from carbon dioxide at all, as plants typically absorb nitrogen in forms such as nitrates or ammonium. Thus, carbon is the directly relevant element related to atmospheric CO2 in the context of plant growth.