<P> In the 3D ideal chain model in chemistry, two angles are necessary to describe the orientation of each monomer . </P> <P> It is often useful to specify quadratic degrees of freedom . These are degrees of freedom that contribute in a quadratic function to the energy of the system . </P> <P> In three - dimensional space, three degrees of freedom are associated with the movement of a particle . A diatomic gas molecule has 5 degrees of freedom . This set may be decomposed in terms of translations, rotations, and vibrations of the molecule . The center of mass motion of the entire molecule accounts for 3 degrees of freedom . In addition, the molecule has two rotational degrees of motion and one vibrational mode . The rotations occur around the two axes perpendicular to the line between the two atoms . The rotation around the atom--atom bond is not a physical rotation . This yields, for a diatomic molecule, a decomposition of: </P> <Dl> <Dd> N = 6 = 3 + 2 + 1 . (\ displaystyle N = 6 = 3 + 2 + 1 .) </Dd> </Dl>

Write the number of degrees of freedom of a diatomic gas molecule