posted by Josh .
An atom of potassium (K) has 19 protons: 18 electrons in its inner electron energy levels and 1 electron in its outer energy level. What is the easiest way for this atom to get a filled outer energy level?
What is formed?
The easiest way is for the K atom to lose that one outside electron to leave all of the inner shells remaining that are filled. That leaves a K ion, K^+.