Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

[Q]: Question: What changes nitrogen gas from the atmosphere to nitrogen compounds that plants can absorb? Answer: bacteria
[A]: Bacteria change nitrogen gas from the atmosphere to nitrogen compounds that plants can absorb.

[Q]: Question: What occurs when two wave crests overlap? Answer: constructive interference
[A]: Constructive interference occurs when two wave crests overlap, doubling the wave amplitude at that location.

[Q]: Question: How many valence electrons does nitrogen have? Answer: 5
[A]:
Nitrogen is a diatomic element with five valence electrons. Create a model of a molecule of nitrogen.