When should we speak of hydrogen atoms rather than hydrogen molecules....?

Jul 11, 2017

When the circumstances demand it. You have the same mass of hydrogen in either scenario.........

Explanation:

Chemists sometimes speak of $\text{dihydrogen}$ in order to distinguish this from $\text{ATOMIC hydrogen}$. In either scenario you have differentiate between $\text{dihydrogen gas}$ and $\text{atomic hydrogen}$.....i.e. you yourself specify the molecularity.