How many valence electrons are present in a Potassium atom?

Valence electrons:

• The electrons which are distributed in the outermost shell of the atom are called valence electrons.

Valence electrons in a Potassium atom:

• The element Potassium$\left(\mathrm{K}\right)$ is in the fourth period and belongs to the alkali metal group (group 1).
• The atomic number of Potassium$\left(\mathrm{K}\right)$ is 19.
• The electronic configuration of Potassium$\left(\mathrm{K}\right)$ can be written as $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^1$
• The valence electrons are the electrons present in the outermost shell, that is $4\mathrm{s}$ subshell contains one electron which means, the valence electron is 1.

Therefore, the valence electron in a Potassium$\left(\mathrm{K}\right)$ atom is 1.