- Allotropy: The existence of two or more alternative forms of the same element in the same physical state.
- Two allotropes of oxygen are:
- Molecular oxygen (O2), also known as diatomic oxygen.
- Ozone (O3), also known as triatomic oxygen.
|Melting point||– 219°C||– 193°C||Ozone has a higher molecular mass than oxygen, and thus requires more energy in order to change state|
|Boiling point||– 183°C||– 111°C||(Same as for melting point, above)|
|Density||About the same as air||About 1.5 times that of air||Ozone is a larger molecule than oxygen|
|Solubility in water||Sparingly soluble||Considerably more soluble than oxygen||Ozone is slightly polar, while oxygen is non-polar|
|Stability||Very stable||Easily decomposed||It is much easier for ozone’s single coordinate covalent bond to be broken than oxygen’s double covalent bond|
|Oxidising strength||Moderately strong||Very strong||(Same as for stability, above)|
Properties of molecular oxygen and ozone