Oxygen
---
| General Properties | |
|---|---|
| Atomic number | 8 |
| Atomic mass | 15.999amu |
| Atomic radius | 48pm |
| Electron Configuration | [He] 2s2 2p4 |
| Density | 0.0013g/cm3 |
| Melting point | -218.79°C |
| Boiling point | -182.962°C |
| First discovered/ developed | 1774 |
| Most common compound on Earth | O2 (Oxygen gas) |
---
Description and uses
Oxygen is the 8th element of the periodic table, and it is the most abundant element in the Earth's crust by weight. It is the source of
fires, and animal life itself. It was discovered by several people all around 1774. It is diatomic, meaning it is naturally found in pairs of atoms bonded together.
Oxygen is one of the sources of fire. Fire is produced by either complete oxygen (if there is a lot of oxygen available) or incomplete oxygen (if there is not a
lot of oxygen available). For complete combustion, the general formula is fuel + oxygen → carbon dioxide + water. For incomplete combustion, the general formula
is fuel + oxygen → carbon monoxide + water. Both reactions need high heats to start, depending on the flammability of the fuel.
It is mainly produced naturally via a process called photosynthesis in plants. It is a reaction catalysed by chlorophyll:
C6H12O6 + 6 CO2 → 6 H2O + 6O2 (glucose + carbon dioxide → water + oxygen gas). Animals, and
other respiring organisms use oxygen to release energy in respiration: 6 H2O + 6O2 → C6H12O6 +
6 CO2 (water + oxygen gas → glucose + carbon dioxide).
Oxygen has 3 naturally occurring isotopes, with atomic weight ranging from 16 to 18. The most abundant isotope is 16O, taking up 99.8% of all oxygen
atoms.