Chlorine
💧 In Your World
Chlorine is a powerful disinfectant that keeps our water safe. It's used to treat drinking water and to keep swimming pools clean. It's the active ingredient in bleach, used for whitening clothes and sanitizing surfaces. Chlorine is also a key component of table salt (NaCl) and is used to manufacture a huge range of products, including plastics like PVC.
📖 The Discovery Story
Chlorine gas was first prepared in 1774 by Swedish chemist Carl Wilhelm Scheele, who mistakenly thought it contained oxygen. In 1810, Sir Humphry Davy insisted that it was a distinct element. He named it "chlorine" from the Greek word khloros, meaning "pale green" or "greenish-yellow," which describes the color of the gas.
📊 Properties at a Glance
| Phase at STP | Gas |
| Melting Point | -101.5 °C / -150.7 °F |
| Boiling Point | -34.04 °C / -29.27 °F |
| Electron Configuration | [Ne] 3s²3p⁵ |
| Abundance in Earth's Crust | 0.017% |
⚠️ Safety & Handling
Chlorine gas (Cl₂) is highly toxic and corrosive. It is a severe irritant to the respiratory system and eyes. Due to its toxicity, it was used as a chemical weapon in World War I. It must be handled with extreme caution in well-ventilated areas, using appropriate protective equipment.