What does 2H represent ?

1. two atoms of hydrogen
2. two molecules of hydrogen
3. one molecule of hydrogen
4. none of the above

two atoms of hydrogen

Reason — The symbol H represents one atom of hydrogen. When a number is written before a symbol, it shows the number of separate atoms. Therefore, 2H means two separate atoms of hydrogen.
It does not represent two molecules of hydrogen because a molecule of hydrogen is written as H₂, not H.