What is the element with the electron configuration #1s^2 2s^2 2p^6 3s^2 3p^6 4s^1#?
Well, there are 19 electrons so...........
So if the the element is neutral (and we must presume it to be!) there are 19 protons in the element's nucleus. And if there are 19 nuclear protons,
Where's my Periodic Table?