Answer:
interaction of light and atoms
emission and absorption of light
It is true that earth is consist of 70% water. However it is still a problem that in the near future, their might be a water shortage that will happened. This is because now mostly of our water sources are no longer clean. Our water are polluted and when time will come water will be very pricey
IDK.
I don't know.
I don't understand the question.