Answer:
Chlorine
It has 7 electrons in it last shell. it will gain one electron to complete its octet and become Cl-. The ionic bond of chlorine form with potassium is Kcl ( potassium chloride)
- Phosphorus has 5 electrons in its last shell it need 3 more electron to stable .
- Sulphur has 6 electron. it needs 2 electrons
- Argon is already stable as it has 8 electrons in its last shell it will not gain or loose any electrons
