Which metal is more reactive: potassium or aluminium?

Potassium is classified as one of the most reactive metals in the alkali metal group, primarily due to its electronic configuration. It has one electron in its outermost shell, making it highly eager to lose that electron in chemical reactions. This strong tendency to react allows potassium to easily participate in various chemical processes, including reactions with water and halogens.

Aluminium, while also reactive, is less so than potassium due to its higher ionization energy and the protective oxide layer that forms on its surface, which can hinder further reaction. Hence, when comparing the two, potassium's reactivity surpasses that of aluminium, making it the more reactive metal in this scenario.