Electronic Spectra Ultraviolet and Visible Spectroscopy

In Section 10-2, we explained that organic molecules may absorb radiation at various wavelengths. Spectroscopy is possible because absorption is restricted to quanta of defined energies, hv, to effect specific excitations with energy change A . 

Sunlight is spiit into its component coiors (the visibie spectmm) by raindrops to give a rainbow. 

Ultraviolet and visible light give rise to electronic excitations 

Nonbonding [as found in lone electron pairs or the propenyl (allyl) radical] 

The orange-red /3-carotene and deep blue azulene differ in their 77-electronic structure. 

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