What element has the symbol 'Cl'?

The story behind the answer

Cl is the symbol for chlorine, a greenish-yellow halogen (group 17) known for its strong disinfecting power. It’s found in common salt (NaCl) and is used to purify drinking water and swimming pools. The name comes from the Greek “chloros,” meaning greenish-yellow, reflecting its gas color.

To avoid mix-ups: C is Carbon, Ca is Calcium, and Co is Cobalt—only Cl matches ChLorine. Memory tip: “ChLorine CLeans water” → Cl. Chlorine was first studied by Carl