Answer:
Explanation:
in a room with no windows that way it doesnt shatter. Usually a closet... or if you have a basement.sorry but that applies to all them
Honestly I don’t really know in my opinion
Answer:

Explanation:
It is given that,
Initially, the electron is in n = 7 energy level. When it relaxes to a lower energy level, emitting light of 397 nm. We need to find the value of n for the level to which the electron relaxed. It can be calculate using the formula as :


R = Rydberg constant, 

Solving above equation we get the value of final n is,

or

So, it will relax in the n = 2. Hence, this is the required solution.
Yes echolocation is based on the use of sound and knowing where the sound comes from without having to look for it a lot of soldiers on the battle field need to know how to use echolocation so they can basically not die