What Is Chlorine?

Chlorine, the seventeenth element on the periodic table, is a greenish-yellow gas with a sharp smell. This reactive halogen is a powerhouse in sanitation and chemistry.

Atomic Number: 17

Symbol: Cl

Atomic Mass: 35.45 u

Category: Halogen

State at Room Temperature: Gas

Discovered By: Carl Wilhelm Scheele (1774)

⚛️ Atomic Structure of Chlorine

Chlorine has seventeen protons, eighteen neutrons (in its most common isotope, Chlorine-35), and seventeen electrons, with seven in its outer shell.

  • 🟢 Protons: 17
  • 🔴 Neutrons: 18 (Most common isotope, Chlorine-35)
  • 🟡 Electrons: 17

💡 Did you know? Chlorine-37, another stable isotope, makes up about 24% of natural chlorine and is used in scientific studies!

🔬 Chlorine Properties

Chlorine is highly reactive, forming compounds with most elements. It's toxic and has a strong, pungent odor, detectable even at low concentrations.

🧪 How Was Chlorine Discovered?

In 1774, Swedish chemist Carl Wilhelm Scheele produced Chlorine by reacting manganese dioxide with hydrochloric acid, though he didn't recognize it as an element.

⚡ Uses of Chlorine

  • 💧 Water Treatment: Disinfects drinking water and pools.
  • 🏭 Industry: Produces plastics (e.g., PVC), bleach, and solvents.
  • 🧪 Chemistry: Used in synthesizing pharmaceuticals and dyes.
  • 🧂 Salt: Found in sodium chloride (NaCl).

💡 Fun Facts About Chlorine

  • 🌊 Essential for making seawater salty.
  • ☠️ Used as a chemical weapon in World War I.
  • 🔬 Second most abundant halogen in Earth's crust.
  • 🌈 Liquid chlorine is bright yellow at -34°C (-29°F).

⚠️ Safety & Precautions

Chlorine gas is toxic and irritating to the lungs, eyes, and skin. It requires careful handling in well-ventilated areas or sealed systems.

🔬 Explore More Elements