In this question given concerning the atom's electron, the number of energy sublevels present in the principal energy level n = 4 is to be determined. For this matter, it should be remembered that the number of sublevels of a certain principal energy level is equal to n. For this item, the number of sublevels is also 4. That is s, p, d and f.
Answer: Coastlines.
Explanation: South America's and Africa's shoreline interlocks perfectly. Which implies they must have been joined together in history.
