Answer:MORE THAN 50 STUDIES WERE CONDUCTED
THE US PUBLIC HEALTH SERVICE WAS RESPONSIBLE FOR PART OF THE STUDY
Explanation: Just completed the assignment Egenuity , i hope this helps .
"n" represents principal energy level or principal quantum number. Principal energy levels are then subdivided into sublevels. The level of principal energy level is always equal to number of sublevels. Therefore if <span>principal energy level</span> = 4, then there are also 4 sublevels present, namely: 4s, 4p, 4d and 4f sublevels.