Oxygen (O)
| Atomic Number | 8 |
|---|---|
| Atomic Mass | 15.999 u |
| Category | Diatomic nonmetal |
| Electron Config | [He] 2s² 2p⁴ |
| Appearance | colorless gas |
| Density (STP) | 1.429 g/L |
| Melting Point | 54.36 K |
| Boiling Point | 90.188 K |
| Electronegativity | 3.44 (Pauling) |
| Ionization Energy | 1313.9 kJ/mol |
| Atomic Radius | 60 pm |
| Crystal Structure | Base-centered Monoclinic |
| Discovered By | Carl Wilhelm Scheele (1774) |
Brief Introduction
Oxygen (O) is a colorless, odorless, tasteless diatomic gas that is essential for most life forms and is the third most abundant element in the universe. It is highly reactive and supports combustion. Key details about Oxygen (O) are as follows:
Uses: Vital for respiration in most living organisms, used in steelmaking and metal fabrication, medical applications (oxygen therapy, ventilators), wastewater treatment, rocket propulsion (liquid oxygen as oxidizer), and welding/cutting (oxy-acetylene).
Production/Extraction: Produced industrially through fractional distillation of liquid air (cryogenic separation). Also generated via pressure swing adsorption (PSA), membrane separation, and electrolysis of water. Makes up 21% of Earth's atmosphere.
History: Discovered independently by Carl Wilhelm Scheele (1772) and Joseph Priestley (1774), though Scheele's work was published later. Antoine Lavoisier named it "oxygen" (Greek for "acid-former") in 1777 and recognized its role in combustion.
Health Effects & Safety: Essential for aerobic respiration, but pure oxygen at high pressures is toxic (oxygen toxicity). Strongly supports combustion, creating fire hazards. Ozone (O₃), an allotrope, is toxic but protects against UV radiation in the stratosphere.
Price/Market: Relatively inexpensive due to atmospheric abundance. Medical-grade and high-purity oxygen command higher prices. Critical for healthcare and industrial sectors.
Properties: Paramagnetic in gaseous form, exists as O₂ (dioxygen) and O₃ (ozone), highly electronegative, forms oxides with almost all elements, and is pale blue in liquid and solid forms.
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