Transition Metal: d-block elements are said to be transition metals, d-block is situated between s-block and p-block.
In s-block every element are metal and in p-block most of the elements are nonmetal. As the d-block is the transition block that the property is shifted from metal to nonmetal.
Potassium is an s-block element.
Potassium is studied as an alkali metal.
For better understanding the periodic table is given below-