Question

Indicate the ground state and the excited state of:
Lithium
Potassium
Sodium
Calcium

Answer 1

Lithium:

$Ground\ state:1s^2\ 2s^1\\excited\ state:1s ^2\ 2s^0\ 2p^1$

Potassium:

$Ground \ state:1s^2\ 2s^2\ 2p^6\ 3s^2\ 3p^6\ 4s^1\\excited state:1s^2\ 2s^2\ 2p^6\ 3s^2\ 3p^6\ 4s^0\ 4p^1$

Sodium;

$Ground state:1s^2\ 2s^2\ 2p^6\ 3s^1\\excited \ state:1s^2\ 2s^2\ 2p^6\ 3s^0\ 3p^1$

Calcium:

$Ground \ state:1s^2\ 2s^2\ 2p^6\ 3s^2\ 3p^6\ 4s^2\\excited state:1s^2\ 2s^2\ 2p^6\ 3s^2\ 3p^6\ 4s^1\ 4p^1$