Spectroscopy

what is electromagnetic radiation?

energy that displays both particle and wave properties

what is a photon?

a particle of electromagnetic radiation

energy formula

e = hv

velocity of light ( c ) formula

c = wavelengthv

what is polychromatic light

light which contains radiation of more than one wave length

what does energy of a monochromatic radiation depend on?

the frequency or wavelength of its waves

what does monochromatic mean

single wavelength

which region carries more photons , UV or IR?

UV

the greater energy of the photon…

the more powerful the radiation

when can an atom absorb photons

unless the photons have enough energy to bring about transition of electrons from one energy level to another

what is a chromophore

part of a molecule that is responsible for a UV or visible absorption spectrum

types of chromophores

carbonyl compounds and aromatics

how can you create a higher frequency of absorption

extra double bonds

what absorbs UV light

a chromophore

how are some chromophores coloured?

because they contain so many long chromophores so they absorb in the visible region

what must be present if any peaks are recorded in a molecule

a chromophore

what are the phamaceutical apps of IR

fingerprint check and identifying drungs

a way to identify functional groups within a molecule

what is an electronic transition

a transition of an electron between different energy levels

where does electronic transitions take place

absorption and fluorescence

what two additional radiation induced transitions do molecules exhibit

vibrational and rotational

IR radiation energy facts

low energy, just enough to bond stretch

to absorb IR what should the bond be

polarisable

what molecules do not display absorbance

fully symmetrical molecules

what 2 things does absorption frequency depend on

mass of the atoms and strength of the bond

the lighter the atom…

the higher the frequency of absoption

the stronger the bond…

the higher the frequency

what is the fingerprint region

between 1500 - 400 cm as there are unique patterns

what is the area between 4000-1500 called

group frequency region