Multiple choice

When liquid water turns into a vapor (gas), how would its molecular structure be written?

  1. H3O

  2. HO2

  3. CH2O

  4. H2O

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A phase change from liquid to gas does not alter the chemical identity of a substance. Therefore, water vapor has the exact same molecular formula as liquid water, which is H2O.