Answer: Sodium has 11 electrons with its electronic configuration as 1s2, 2s2, 2p6, 3s1.
Potassium has 19 electrons with its electronic configuration as 1s2, 2s2, 2p6, 3s2, 3p6, 4s1.
Both sodium and potassium have one electron in their outermost (valence) shell (3s1 and 4s1 respectively) hence they belong to group 1 in the periodic table and form a +1 ion by loss of its valence electron (one electron)
Explanation: Sodium and potassium has one valence electron, hence they are group 1 elements. Elements are grouped in the periodic table according to the number of their valence electrons.
In writing the electronic configuration of elements, there are s, p, d, f orbitals. s orbital can contain a maximum of two electrons, d orbital can contain a maximum of six electrons, d orbital can contain a maximum of ten electrons while f orbital can contain a maximum of fourteen electrons. The filling of the orbitals follows the order: 1s, 2s, 2p, 3s, 3p, 4s etc.