For molecular vibrations, the frequency of a stretching vibration is given by the following equation:

Question

Frequency (wavenumber) = 4.12 × √(K/)
where K is the force constant of the bond and  (reduced mass) = (m1m2)/(m1+m2), where m is the mass of the atoms.
If the stretching frequency of the O-H bond in water is 3280 cm-1, calculate the stretching frequency of O-D bond in D2O. (Assume that the force constants of the O-H and O-D bonds are similar).