answer: focus or hypocenter
enplanation: when energy release at the focus, seismic waves travel outward from that point in all directions.
The answer is 4.
Gases have low densities, because of the increased space between hight-energy particles.
Answer to this question is C. Regarding the volume.
To test if the hypothesis is correct, a good way is to think of it this way:
Density = mass/volume, right?
Calculate the mass and volume of each and do the equation; this will test your hypothesis.
You will be left with the density of each. But, make sure that the sample sizes are the same (controlled variable) otherwise it will be an unfair test.
