Answer:
A longitudinal wave is a wave where the movement of the medium is in the same direction as the wave. On the other hand, a transverse wave is a wave where the movement of the medium is at a right angle to the wave direction.
Explanation:i got this right on a quiz so i know its right
Choices 'a', 'c', and 'd' are true.
In choice 'b', I'm not sure what it means when it says that masses
are 'balanced'. To me, masses are only balanced when they're on
a see-saw, or on opposite ends of a rope that goes over a pulley.
Maybe the statement means that the mass of the nucleus and the
mass of the electron cloud are equal. This is way false. It takes
more than 1,800 electrons to make the mass of ONE proton or
neutron, and the most complex atom in nature only has 92 electrons
in it. So there's no way that the masses of the nucleus and the electrons
in one atom could ever be anywhere near equal.
Answer:

Explanation:
Density can be found by dividing the mass by the volume.

The mass of the quartz is 30 grams and the volume is 6 cubic centimeters.

Substitute the values into the formula.

Divide.

The density of this piece of quartz is 5 grams per cubic centimeter.
A
More concentrated means more collisions per unit volume, and as the volume stays the same and only concentration changes, the there are more collisions