Question

which process occurs when bacteria converts nitrogen gas to a usable form? decomposition condensation fixation transpiration

Explanation:

• Decomposition is the breakdown of organic matter.
• Condensation is the change of gas to liquid.
• Transpiration is water movement through plants.
• Nitrogen fixation is the process where bacteria convert nitrogen gas ($N_2$) to a usable form (like ammonia - $NH_3$).

Answer:

fixation