Emission vs Absorption Spectra | Absorption Spectrum vs Emission Spectrum
Lub teeb thiab lwm hom hluav taws xob hluav taws xob muaj txiaj ntsig zoo, thiab siv dav hauv chemistry analytical. Kev sib cuam tshuam ntawm hluav taws xob thiab teeb meem yog qhov kev tshawb fawb hu ua spectroscopy. Molecules lossis atoms tuaj yeem nqus tau lub zog lossis tso tawm lub zog. Cov zog no tau kawm hauv spectroscopy. Muaj cov spectrophotometers sib txawv los ntsuas ntau hom hluav taws xob hluav taws xob xws li IR, UV, pom, X-ray, microwave, xov tooj cua zaus, thiab lwm yam.
Emission Spectra
Thaum muab cov qauv, peb tuaj yeem tau txais cov ntaub ntawv hais txog tus qauv nyob ntawm nws qhov kev cuam tshuam nrog hluav taws xob. Ua ntej, cov qauv yog txhawb nqa los ntawm kev siv lub zog hauv daim ntawv ntawm cov cua sov, hluav taws xob, lub teeb, cov khoom, lossis cov tshuaj tiv thaiv. Ua ntej siv lub zog, cov molecules hauv cov qauv yog nyob rau hauv lub zog qis zog, uas peb hu ua lub xeev hauv av. Tom qab siv lub zog sab nraud, qee qhov ntawm cov molecules yuav raug hloov mus rau lub zog siab dua hu ua lub xeev zoo siab. Lub xeev zoo siab no tsis ruaj khov; yog li ntawd, sim emit zog thiab rov qab los rau hauv av xeev. Qhov hluav taws xob tso tawm no yog npaj ua haujlwm ntawm zaus lossis wavelength, thiab nws yog hu ua emission spectra. Txhua lub ntsiab emits cov hluav taws xob tshwj xeeb nyob ntawm lub zog sib txawv ntawm lub xeev hauv av thiab lub xeev zoo siab. Yog li, qhov no tuaj yeem siv los txheeb xyuas hom tshuaj.
Absorption Spectra
Ib qhov nqus spectrum yog ib zajlus ntawm absorbance piv rau wavelength. Lwm yam tshaj li qhov nthwv dej ntev absorbance kuj tuaj yeem npaj tawm tsam zaus lossis yoj tus lej. Absorption spectra tuaj yeem yog ob hom xws li atomic absorption spectra thiab molecular absorption spectra. Thaum lub beam ntawm polychromatic UV los yog pom hluav taws xob kis tau los ntawm atoms nyob rau hauv cov roj theem, tsuas yog ib co ntawm cov zaus yog absorbed los ntawm lub atoms. Absorbed zaus sib txawv rau txawv atoms. Thaum cov hluav taws xob xa hluav taws xob tau kaw, lub spectrum muaj ntau txoj kab nqaim heev. Nyob rau hauv atoms, cov absorption spectra yog pom los ntawm kev hloov hluav taws xob. Hauv cov molecules, tsis yog kev hloov hluav taws xob, kev vibration thiab kev hloov pauv kuj tseem ua tau. Yog li qhov nqus spectrum yog qhov nyuaj heev, thiab cov molecule absorbs UV, IR thiab pom hluav taws xob hom.
Qhov txawv ntawm Absorption spectra Vs emission spectra yog dab tsi?
• Thaum lub atom lossis molecule excites, nws absorbs ib lub zog nyob rau hauv lub electromagnetic tawg; Yog li ntawd, lub wavelength yuav tsis nyob rau hauv lub kaw lus nqus spectrum.
• Thaum cov tsiaj rov qab los rau hauv av los ntawm lub xeev zoo siab, cov hluav taws xob nqus tau tawm, thiab nws raug kaw. Hom spectrum no hu ua emission spectrum.
• Hauv cov ntsiab lus yooj yim, kev nqus spectra sau cov wavelengths absorbed los ntawm cov khoom, whereas emission spectra cov ntaub ntawv wavelengths emitted los ntawm cov ntaub ntawv, uas tau raug txhawb los ntawm lub zog ua ntej.
• Piv rau qhov pom tsis tu ncua, ob qho tib si emission thiab absorption spectra yog kab spectra vim lawv tsuas muaj qee qhov wavelengths.
• Nyob rau hauv ib qho emission spectrum yuav tsuas muaj ob peb xim xim nyob rau hauv ib tug tsaus nti rov qab hauv av. Tab sis nyob rau hauv ib qho kev nqus spectrum yuav muaj ob peb qhov tsaus nti bands nyob rau hauv tas li spectrum. Cov kab tsaus nti hauv qhov nqus spectrum thiab cov xim xim hauv cov emitted spectrum ntawm tib lub ntsiab lus zoo sib xws.
