Final answer:
The correct dot notation for the positively charged potassium ion is 'K+' which symbolizes that potassium has lost one valence electron and become a monovalent cation.
Step-by-step explanation:
The correct dot notation for the element potassium (K) is represented by the letter 'K' followed by a plus sign as a superscript. Therefore, when potassium loses an electron to form a cation, it is denoted as K⁺. This indicates that the potassium atom has given up its single valence electron and now carries a positive charge. The cations are designated by the symbol for the parent element and a plus charge as a superscript after the element symbol. As potassium is monovalent, losing one electron results in a +1 charge. This forms the basis of the potassium ion's role in chemical reactions and electrolyte balance within the body.