Question

What is the electron configuration for `Fr`?

Answer 1

`[Rn]7s^1`

Explanation:

From the Periodic Table, `Z`, the atomic number of `Fr=87`

And thus,

`1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(10)4s^(2)4p^(6)4d^(10)5s^(2)5p^(6)4f^(14)5d^(10)6s^(2)6p^(6)7s^1`

Well, I have got 87 electrons there at least. Of course, all the action, all the chemistry takes place at `7s^1`, i.e. `Fr` is univalent and would react as an alkali metal. It is extremely rare element and gram quantities would be unknown.