Answer:
I think it's answer would be A
My Choice will be the sample C with a coefficient of absorption 62 % and the reason is that the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest. Because this sample has the highest percentage of the coefficient of absorption than the other samples, As the sound Absorption coefficient is a part of the sound energy that absorbed by a material.And Its value varies with the angles of incident and frequency. So sample C is the best to be used as a soundproof room.
Answer:
The number of valence electrons increases from top to bottom within each group.
Explanation:
The valence electrons are the outermost shell electrons.
Therefore, the number of valence electrons does not increase from top to bottom within each of the group.
Down a group, the number of valence electrons remains the same.
For group I elements, the number of electrons is 1.
The group is the vertical arrangement of elements.
From left to right across a period, the number of valence electrons increases because you move from group to group.
