Question

the ion k+ has
gained one electron
gained one proton
lost one electron
lost one proton

Explanation:

Atoms become positively - charged ions by losing electrons. Potassium (K) has an atomic number of 19. When it forms a K⁺ ion, it loses one electron to achieve a stable electron configuration. Protons are not lost or gained in normal chemical reactions to form ions.

Answer:

C. lost one electron