how can you go from molar mass to density if its not a gas
molar mass = 20.0276 g/mol
The Attempt at a Solution
It's not extra protons in D2O, it's extra neutrons.Hi Cory, welcome to PF!
Compare the number of D2O molecules in unit volume to that of water. Do the extra protons change the size and interaction between the molecules appreciably with respect to H2O?