Potassium is most likely to form a potassium ion, denoted as K+. When potassium loses one electron, it achieves a stable electronic configuration similar to that of noble gases. The loss of this electron gives potassium a positive charge, making it a cation.
In the case of potassium, it has one electron in its outermost shell (the fourth shell). To attain a stable state, it prefers to lose this electron, resulting in a positively charged ion. Since cations are positively charged ions formed by the loss of electrons, K+ is classified as a cation.