1. The problem statement, all variables and given/known data A triatomic molecule consists of 3 atoms arranged along a straight line. The molecules can translate and rotate but not vibrate. How many degrees of freedom are associated with this molecule? 2. Relevant equations Molar Heat Capacity of Gases: Cv = f/2(R) f - degrees of freedom 3. The attempt at a solution I figured that a triatomic gas would have the same translational motion as that of a monoatomic and diatomic molecule and it would have perhaps more axes of rotational motion than diatomic molecules. And from seeing that diatomic molecules have 5 degrees of freedom after ignoring vibrational motion, I am assuming that you can drop vibrational motion for triatomic molecules as well. Would I be correct in concluding that a triatomic molecule has 6 degrees of freedom? I came to this conclusion by one more rotational axis. I'm not sure this is correct, however. Any help would be greatly appreciated.