SPECTROSCOPY

The entrance slit

The collimating lens

None of these

The diffraction grating

when the amplitudes are the same.

when the frequencies match exactly

at no time.

at anytime.

none of these

σ → σ*

n → σ*

n → π* and π → π*

an Infrared spectroscopy

a class of spectroscopic techniques which analyzes molecular motions

a large mass on a weak spring

a flashlight through a prism and shake it

Because rotational transitions are extremely rare

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

All of these

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