Why does one electron in a potassium atom go into the fourth energy level instead of squeezing into the third energy level along with the eight already there?

Answer it is also known as the completion state is untrue of the activation complex;

Atp, shorthand for adenosine triphosphate, is the standard molecule for cellular enger in the human body. all motion and metabolic  processes  within the body begins with energy that is released from  atp, as its phosphate bonds are broken in cells through a  process  called hydrolysis.