Question

which type of molecules do not show rotational spectra?​

Answer 1

Answer:

Spherical top molecules have no net dipole moment. A pure rotational spectrum cannot be observed by absorption or emission spectroscopy because there is no permanent dipole moment whose rotation can be accelerated by the electric field of an incident photon.

Answer 2

Answer:

H2O,hcl,CO2 ,N2O does not show rotational spectra