# Calculate number of electrons per shell for an atom

Suppose you are given the atomic number of an element, e.g. Technetium, which is 43. Is it possible to return an array which shows the distribution of electrons across different shells of an atom using vanilla JavaScript?

Example Input/Output:

Atomic number Electronic configuration
20 (Calcium) [2, 8, 8, 2]
43 (Technetium) [2, 8, 18, 13, 2]
50 (Tin) [2, 8, 18, 18, 4]