* Hydrogen's boiling point: -252.87°C (-423.17°F)
* Oxygen's boiling point: -182.95°C (-297.31°F)
The reason for this difference is due to the strength of the intermolecular forces between the molecules.
* Hydrogen: Hydrogen molecules are very small and have only weak London dispersion forces between them. This means they don't need much energy to overcome these forces and transition from a liquid to a gas.
* Oxygen: Oxygen molecules are larger and have stronger London dispersion forces, making them more difficult to separate and requiring a higher temperature (higher energy input) to reach their boiling point.
