1. The problem statement, all variables and given/known data The question goes something like this: What % of inter atomic separation is the root mean amplitude. The data given is: Inter atomic separation : 0.29nm , T =300k , D = 20 N/m , Aluminium atomic weight 27 g/mole. How do I proceed I have no idea on how to relate mean inter atomic separation and rms of the amplitude. 2. Relevant equations Formula to calculate Root mean amplitude is : √KbT/D 3. The attempt at a solution As above.