20 x 5 = 100
so 1 less than that
19 x 5 = 95
500 = 5 x 100 500 - 475 = 25 = 5 x 5 100 - 5 = 95
21 5s
In the Rb atom, the electron configuration is [Kr]5s^1. This means there is 1 electron in the 5s sublevel of the Rb atom.
24
10
20
90
75
7
i think there are 18 digit 5s.
66 of them.
Exactly 33 of them