A sound wave travels through air. In which regions of the wave are air molecules the least dense? *

A. compressions
B. crests
C. rarefactions
D. troughs

The air that we breath is made mostly of which gaseous molecule

What are some important factors to consider when choosing a warm-up before your workout?

Earth's atmosphere is composed of mostly two gases. name the two gases that make up the majority of the atmosphere and use the pie chart to tell the percentages of each.