Periodic table / Chlorine

Overview

Chlorine is a chemical element with symbol Cl and atomic number 17. It also has a relative atomic mass of 35.5. Chlorine is in the halogen group (17) and is the second lightest halogen following fluorine.

Electron configuration

The electron configuration of Chlorine is [Ne] 3s2 3p5, with electron shells of 2, 8, 7.

Physical and chemical properties

Chlorine is classified as a nonmetal. It has an atomic mass of 35.45 and exists as a gas at standard conditions, appearing as pale yellow-green gas.

Real-world uses of Chlorine

Chlorine plays an important role in chemistry and biology, and is used in industrial processes, manufacturing, or as a key component of compounds essential to life.

Interesting facts about Chlorine

• Chlorine has the atomic number 17 and chemical symbol Cl.
• It belongs to period 3, group 17 of the periodic table.
• Chlorine was discovered by Carl Wilhelm Scheele.

Explore Chlorine interactively

Want to compare Chlorine with other elements or see it highlighted on the full table? Open the interactive periodic table and click on Cl to explore properties, trends, and neighboring elements. You can also test your knowledge with our periodic table quiz game.