Respuesta :

Na:-

Sodium has 11 electrons so the EC followed by

[tex]\\ \sf\Rrightarrow 1s^22s^22p^63s^1[/tex]

Ca:-

Calcium has 20electrons so the EC followed by

[tex]\\ \sf\Rrightarrow 1s^22s^22p^63s^23p^63d^2[/tex]