| Formula / Notation | O2 |
|---|---|
| CAS Number | 7782-44-7 |
| Molecular Weight | 16.0 |
| Melting Point | -218.4 |
| Boiling Point | -183.0 |
| Density | 0.00143 |
| Solubility | 44 mg/L at 25 C |
| Appearance | Colourless, odourless diatomic gas; pale blue as liquid |
| Also Known As | O2, oxygen gas |
| Category | Elements |
What is Oxygen?
Oxygen is a colourless, odourless diatomic gas, atomic number 8, the most abundant element in Earth crust (46% by mass). Essential for aerobic respiration and combustion. Supports burning but does not itself burn.
Formula & Notation
IUPAC Name: Dioxygen
Other Names / Synonyms: O2, oxygen gas
Properties & Characteristics
Physical Data
| Property | Value |
|---|---|
| Melting Point | -218.4 |
| Boiling Point | -183.0 |
| Density | 0.00143 |
| Molecular Weight | 16.0 |
| Solubility | 44 mg/L at 25 C |
| Appearance | Colourless, odourless diatomic gas; pale blue as liquid |
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
Oxygen is a colourless, odourless diatomic gas, atomic number 8, the most abundant element in Earth crust (46% by mass). Essential for aerobic respiration and combustion. Supports burning but does not itself burn.
Steel production (basic oxygen furnace). Medical breathing gas. Rocket propellant (liquid O2 + H2). Water treatment. Oxy-acetylene welding and cutting. Chemical synthesis. Paper bleaching. Respiration.
Vigorously accelerates combustion - oxygen-enriched atmospheres greatly increase fire risk. Liquid oxygen: cryogenic burns (-183 C). Pressurised cylinders: explosion risk if valve damaged. Keep away from oils and greases (explosion risk).
The formula or notation for Oxygen is: O2