Oxygen
💨 In Your World
Oxygen is the very air we breathe and the reason life as we know it exists. It makes up about 21% of Earth's atmosphere and is essential for respiration in most living organisms. It's also the "O" in H₂O, the most abundant compound on Earth's surface. Oxygen's high reactivity makes it a key component in combustion—from a campfire to the engine in a car.
📖 The Discovery Story
Oxygen was discovered independently by Carl Wilhelm Scheele in 1773 and Joseph Priestley in 1774. Priestley is often given more credit because he published his findings first. However, it was Antoine Lavoisier who recognized it as a chemical element and gave it the name "oxygen," from the Greek words oxys (acid) and genes (forming), because he mistakenly believed it was a component of all acids.
📊 Properties at a Glance
| Phase at STP | Gas |
| Melting Point | -218.79 °C / -361.82 °F |
| Boiling Point | -182.96 °C / -297.33 °F |
| Electron Configuration | [He] 2s²2p⁴ |
| Abundance in Earth's Crust | 46.1% (most abundant) |
⚠️ Safety & Handling
While essential for life, pure oxygen can be dangerous. It is a powerful oxidizer and dramatically increases the flammability of other materials. Breathing pure oxygen at high pressures can also be toxic, leading to a condition called oxygen toxicity, which can damage the lungs and central nervous system.