Oooo that ones hard. ummm... idk i think we should just leave it to the experts ya know.
Answer:
A. The amount of mass changes only slightly during a chemical
reaction.
Be heavier
density=mass÷volume
if two items have the same size they have the same volume so the heavier one will be the denser one
The frequency of a simple harmonic oscillator such as a spring-mass system is given by

where
k is the spring constant
m is the mass attached to the spring.
Re-arranging the formula, we get:

and since we know the constant of the spring:

and the frequency of oscillation:
f=1.00 Hz
we can find the value of the mass attached to it:
They are both created by waves of different forms of energy... sound is the oscillation of other substances, called a medium, while the electromagnetic waves are oscillating through electromagnetic energy.