What is the number of waves that go by in a certain amount of time

frequency

Explanation:

The frequency of a wave is the number of cycles the wave complete in one second. It is measured in hertz (Hz) , gigahertz (GHz) or larger scales.

Frequency F is inversely proportional to period T, which is the time it takes a wave to complete a cycle.

I.e Frequency = 1/T

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.