When sound waves hit a solid surface they either reflect, refract, or absorb.
Echo's are caused by the reflection of sound waves.
Answer:
carbon dioxide
Explanation:
carbon dioxide is released into atmosphere
Answer:
An electron in an excited energy level of an atom will always drop to lower energy levels, emitting very specific wavelengths of light in the process.
Answer:
Disagree.
Explanation:
Though some cells are bigger than others, they do not scale with size. For example if you look at skin cells on a dog they would be similar in size to a skin cell from a human. When an animal or species is bigger it is usually just made from more cells.