SPECTROSCOPY

The diffraction grating

The collimating lens

None of these

The entrance slit

at no time.

when the amplitudes are the same.

at anytime.

when the frequencies match exactly

n → π* and π → π*

none of these

σ → σ*

n → σ*

a class of spectroscopic techniques which analyzes molecular motions

an Infrared spectroscopy

a large mass on a weak spring

a flashlight through a prism and shake it

Because, in liquids and solids, spectral lines corresponding to rotational transitions are broadened as the result of molecular collisions and other interactions

Because the energy required to induce a rotational transition is so small that it cannot be measured

Because rotational transitions are extremely rare

All of these