Question

For every element, the ground state electron configuration has at least one electron in the 2s orbital.
True/False
I feel like it is false, but I don't know.

Answer 1

False:
hydrogen in the ground state has only on electron so its configuration is 1s1

helium in the ground state has only 2 electrons so its configuration is 1s2

You don't start filling the 2s orbital until you get to Lithium
Lithium in the ground state is 1s2 2s1

Answer 2

Thanks :)