Answer:
It's the first option. A distance between two similar points on a wave of light.
Explanation:
On a wavelength chart, where you measure the rate at which the light travels at its distance from the source. You have two points to compare to.
it means basically the same thing but can be used in different context. like if someone says, "lets diffuse the situation." it means lets separate it and find out what's going on with it. Like if you don't understand a sentence when you were younger your teacher would tell you to break down the sentence, and try to use context clues. What you are doing is diffusing the sentence so that your not looking at it as one big confusing sentence, your "breaking it down" and that helps you a lot. I hope I helped you, if not let me know and I can diffuse the topic a little more to make it more approachable and easy to understand. :)
1. Figure out a problem
2. Research
3. Hypothesis
4. Experiment
5. Analyze results
6. Conclusion
7. Communicate your results
Hope This Helps. :D <span />
I believe it would be 7.731. x 10^5? That is if they want you to evaluate.