1. The problem statement, all variables and given/known data I can't answer to that question, and I don't know how to. I have to calculate the average separation between H2O molecules in pure water. 2. Relevant equations The diameter of the molecule is 0.29 nm I think we can use the bohr equation to resolve it? r = (ε0*h2) / (π*m*e2) I also found this : ω (which is the average spacing) = 1/n = 4π/3=r03 (from here) 3. The attempt at a solution I don't know.- I don't want the answer just some clue to get the answer. :) Thank you.