chemistry / Analysis / free

Spectroscopy

Read the fingerprints molecules leave in light.

Follow the cause1 / 3

Radiation meets a molecule. A photon interacts when its energy matches an allowed molecular transition.

molecular fingerprintsIR · 4 diagnostic peaks
Focus the idea
A spectrum reveals molecular structure through diagnostic peaksThe IR model shows 4 peaks whose positions change with molecular environment and whose height follows signal intensity.low energy / downfieldhigh energy / upfieldν̃ (cm⁻¹)
methodIR
diagnostic peaks4
largest signal70%
evidencestructure

IR absorption is strongest when a bond vibration changes the molecule's dipole. Peak position suggests the bond type; intensity is a separate clue.

The plotted peaks are teaching signals, not an instrument trace. Real spectra depend on calibration, solvent, coupling, line width, concentration, and instrument resolution.

04 / PRACTICE

Make the chemistry yours.

0 / 3 checked

Answer from the model, then use the explanation to connect the particle picture to the chemical rule.

CHECK 1 / 3

What does an NMR integration mainly estimate?