In hydrogen, why cannot electrons enter an empty shell after the K shell is filled?

How many electrons does hydrogen have? How can the K shell be full?

14 minutes ago, chenbeier said:

How many electrons does hydrogen have? How can the K shell be full

What I meant to say is can a Hydrogen -2 ion be formed?

No, the full k shell is helium structure and very stable. So there can no additional electron to L, the same reason you can not make a He- .

16 minutes ago, chenbeier said:

No, the full k shell is helium structure and very stable. So there can no additional electron to L, the same reason you can not make a He- .

If you bump an electron to  H- ion, can't the electron just enter the empty L shell by releasing energy?

Hydrogen anion H- exists in cosmic space..

https://en.m.wikipedia.org/wiki/Hydrogen_anion

 

1 hour ago, King E said:

What I meant to say is can a Hydrogen -2 ion be formed?

No

The repulsion between the two electrons is too large.

8 minutes ago, Sensei said:

Hydrogen anion H- exists in cosmic space..

https://en.m.wikipedia.org/wiki/Hydrogen_anion

 

Don’t even have to go that far. H- is used in the TRIUMF cyclotron https://fiveyearplan.triumf.ca/teams-tools/520-mev-cyclotron/

But as your link states, there is no bound excited states. Adding a third electron isn’t going to work

H- is easy to get. Hydrogen react with sodium or other Smalltalk.

2 Na + H2 => 2 NaH. Sodiumhydrid.