Answer:
Following are the response to the given question:
Explanation:
The number of shells
n = 4
Calculating the spectral line:

The answer is A i think if it’s wrong someone correct me
If a solution is saturated, that means it already posses the maximum number of solutes thus have been dissolved in it, and thus the concentration cannot be increased.
Answer:
aphelion
Explanation:
A planet moves with constantly changing speed as it moves about its orbit. The fastest a planet moves is at perihelion (closest) and the slowest is at aphelion (farthest).