Write completely the electronic configurations of K and Rb.

Explanation

At. no. of K = 19
Electronic configuration
`=1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(1)`
At. no. of Rb = 37
Electronic configuration
`=1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(10)4s^(2)4p^(6)5s^(1)` .