Rarefraction.
Crest- tallest spot on transverse wave.
Trough- shortest point on transverse wave.
Compression - spot on a compressional wave where the waves are closer together.
Rarefraction - spot on a compressional wave where the waves are farther apart.
Answer:
Helium
Explanation:
Helium is the least reactive element, since it is a noble gas with the smallest amount of valence rings.
I think it should be D as momentum is the product of mass and velocity...
When conducting and experiment you want to have a notebook and something to write down notes with so you can keep everything organized and proper, and to not miss anything in the experiment. Also you want to have everything in order of the way it should be in.
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