A formula reference gives water as H2O. Each hydrogen nucleus has 1 proton and the oxygen nucleus has 8 protons. Enter the total number of protons represented by one water molecule.
Correct answer
10
Explanation
The formula specifies two hydrogen atoms and one oxygen atom, so the proton total is two times 1 plus 8, which equals 10. Treating the formula as HO would omit one hydrogen atom and produce a total that is too small.