Answer;
Chlorine
Step-by-step explanation;
Nonmetals form anions (negative ions). Non-metals typically become negatively charged ions when they bond (with a metal) because it is most energetically favorable for them to gain one ore more electrons to become isoelectronic with the nearest noble gas to their right.
Cations (positively-charged ions) and anions (negatively-charged ions) are formed when a metal loses electrons, and a nonmetal gains those electrons. The electrostatic attraction between the positives and negatives brings the particles together and creates an ionic compound, such as sodium chloride.