🔹 Basic Information

• Element Name: Chlorine
• Discovered By: Carl Wilhelm Scheele
• Year of Discovery: 1774
• Category: Halogen
• Group: 17 (Group VIIA – Halogens)
• State at Room Temperature: Gas (greenish-yellow) ☁️

Chlorine is a pale green, poisonous gas with a strong, sharp smell. It belongs to the halogen family, a group of elements known for being very reactive and often used in disinfectants, salts, and chemical reactions.

🔸 Chemical Properties

• Chemical Symbol: Cl
• Atomic Number: 17
• Atomic Mass: ~35.45 u
• Valency: 1 (commonly), can vary in compounds
• Electronic Configuration: [Ne] 3s² 3p⁵

Chlorine is one electron short of a full outer shell, which makes it highly reactive, especially with metals. It loves forming salts — like the common table salt (NaCl).

📘 Basic Things to Know

Chlorine is a toxic gas in pure form but is widely used in safe, controlled amounts. It’s essential in water treatment and everyday cleaning products. 🧼

In the periodic table, it sits next to fluorine and shares many traits with other halogens — including strong odor, color, and the ability to kill bacteria.

🤔 Interesting Facts

• Chlorine was first mistaken for a compound, not an element.
• The name “chlorine” comes from the Greek word “chloros,” meaning greenish-yellow.
• It’s deadly in large amounts, but in the right dose, it’s what keeps our drinking water safe! 💧
• Chlorine gas was used as a chemical weapon during World War I (a dark chapter in its history).
• It’s part of many daily-use compounds — including PVC plastic and household bleach.

🔧 Common Uses

• Water Purification: Chlorine is added to drinking water and swimming pools to kill bacteria. 🚿🏊
• Disinfectants: Found in bleach and cleaning solutions.
• Plastics: Used to make PVC (polyvinyl chloride) used in pipes, flooring, and more.
• Medicine: Used in the production of medicines and antiseptics.
• Textiles & Paper: Helps bleach paper and fabrics to a bright white color.

📚 Conclusion

Chlorine is a powerful element that plays a huge role in public health and modern industry. It might be dangerous in its pure form, but when used correctly, it’s one of the unsung heroes keeping our lives clean and safe. For students, it’s a great example of how chemistry balances risk and benefit — turning something harmful into something helpful with the right knowledge. 🔍⚖️