Yes, chlorine is classified as a nonmetal. It belongs to group 17 of the periodic table, which includes the halogens. Nonmetals are characterized by their lack of metallic luster, poor conductivity of heat and electricity, and high ionization energies. Chlorine, in its diatomic form (Cl2), is a pale yellow-green gas at room temperature and is known for its strong oxidizing properties.
Chlorine reacts with many elements and compounds, which is typical of nonmetals. Its most common usage is in the production of chlorine-based compounds, such as sodium chloride (table salt), as well as in water treatment processes to purify and disinfect. Being a nonmetal, chlorine also has a tendency to gain electrons during chemical reactions, forming negatively charged ions called anions.