Question

which molecules from the air could potentially be used to make food molecules in plants? check off all that apply.

□ carbon dioxide

□ oxygen

☑ argon

□ methane

☑ hydrogen

□ water vapor

□ helium

☑ nitrogen

Explanation:

Plants produce food molecules via photosynthesis, which uses atmospheric carbon dioxide ($\text{CO}_2$) as a key carbon source. Water vapor (from air or soil) provides hydrogen and oxygen for glucose synthesis. Nitrogen gas from the air is fixed by soil bacteria into forms plants use to build protein-based food molecules. Argon, helium, oxygen, methane, and hydrogen are not used directly to make plant food molecules.

Answer:

carbon dioxide, water vapor, nitrogen