system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does lightning put nitrogen into the Earth?
gpt
The atmosphere is about 80% nitrogen and 20% oxygen. Lightning tears the molecules of these two gasses apart and they recombine back to the original gasses or to nitrogen oxides. These nitrogen oxides combine with water vapor to form nitric acid which rains down and reacts with soil particles to form nitrates which plants can use.