Isotopes vs Isomers
Muaj ntau qhov sib txawv ntawm cov atom sib txawv. Tsis tas li ntawd, muaj cov variations nyob rau hauv tib lub ntsiab. Isotopes yog cov piv txwv rau qhov sib txawv hauv ib lub caij.
Ib lub molecule lossis ion uas muaj tib lub qauv molecular tuaj yeem muaj nyob rau hauv ntau txoj hauv kev nyob ntawm qhov kev txiav txim sib txuas, them nqi sib txawv, txoj kev uas lawv npaj lawv tus kheej hauv qhov chaw thiab lwm yam; cov no hu ua isomers.
Isotopes
Atoms ntawm tib lub ntsiab tuaj yeem sib txawv. Cov atoms sib txawv ntawm tib lub ntsiab yog hu ua isotopes. Lawv sib txawv ntawm ib leeg los ntawm kev sib txawv ntawm cov neutrons. Txij li tus naj npawb neutron txawv, lawv cov lej kuj txawv. Txawm li cas los xij, cov isotopes ntawm tib lub caij muaj tib tus naj npawb ntawm protons thiab neutrons. Cov isotopes sib txawv tam sim no nyob rau hauv ntau qhov sib txawv, thiab qhov no yog muab raws li qhov feem pua tus nqi hu ua txheeb ze abundance. Piv txwv li, hydrogen muaj peb isotopes li protium, deuterium thiab tritium. Lawv tus naj npawb ntawm cov neutrons thiab cov txheeb ze muaj ntau yog raws li hauv qab no.
1H – tsis muaj neutrons, txheeb ze abundance yog 99.985%
2H- ib neutron, txheeb ze abundance yog 0.015%
3H- ob neutrons, txheeb ze abundance yog 0%
Tus naj npawb ntawm neutrons ib lub nucleus tuaj yeem tuav txawv ntawm lub caij mus rau lub caij. Ntawm cov isotopes, tsuas yog qee qhov ruaj khov. Piv txwv li, oxygen muaj peb lub isotopes ruaj khov, thiab tin muaj kaum isotopes ruaj khov. Feem ntau, cov ntsiab lus yooj yim muaj tib tus lej neutron li tus lej proton tab sis, hauv cov ntsiab lus hnyav, ntau cov neutrons muaj ntau dua li cov protons. Tus naj npawb ntawm cov neutrons yog ib qho tseem ceeb kom sib npaug ntawm kev ruaj ntseg ntawm cov nuclei. Thaum cov nuclei hnyav dhau lawm, lawv yuav tsis ruaj khov thiab, yog li ntawd, cov isotopes tau dhau los ua cov xov tooj cua. Piv txwv li, 238 U emits hluav taws xob thiab lwj mus rau ntau lub nuclei me me. Isotopes tuaj yeem muaj cov khoom sib txawv vim lawv qhov sib txawv. Piv txwv li, lawv yuav muaj qhov sib txawv, yog li lawv cov NMR spectra txawv. Txawm li cas los xij, lawv tus lej electron zoo ib yam ua rau muaj kev coj cwj pwm zoo sib xws.
Ib pawg spectrometer tuaj yeem siv tau kom tau txais cov ntaub ntawv hais txog isotopes. Nws muab tus naj npawb ntawm isotopes uas ib qho khoom muaj, lawv cov txheeb ze abundances thiab masses.
Isomers
Isomers yog cov sib xyaw sib txawv nrog tib lub qauv molecular. Muaj ntau hom isomers. Isomers tuaj yeem faib ua ob pawg raws li kev cai lij choj isomers thiab stereo isomers. Constitutional isomers yog isomers qhov twg kev sib txuas ntawm atoms txawv hauv cov molecules. Butane yog qhov yooj yim tshaj plaws alkane los qhia kev cai lij choj isomerism. Butane muaj ob txoj cai isomers, butane nws tus kheej thiab isobutene.
Nyob rau hauv stereo-isomers atoms txuas nrog tib yam, tsis zoo li kev cai lij choj isomers. Stereoisomers txawv tsuas yog nyob rau hauv kev npaj ntawm lawv cov atoms nyob rau hauv qhov chaw. Stereoisomers tuaj yeem yog ob hom, enantiomers thiab diastereomers. Diastereomers yog stereoisomers uas nws cov molecules tsis yog daim iav duab ntawm ib leeg. Cis trans isomers ntawm 1, 2-dichloroethene yog diastereomers. Enantiomers yog cov stereoisomers uas nws cov molecules yog cov duab uas tsis yog superposable daim iav ntawm ib leeg. Enantiomers tshwm sim tsuas yog nrog chiral molecules. Ib qho chiral molecule yog txhais ua ib qho uas tsis zoo ib yam nrog nws daim iav duab. Yog li ntawd, chiral molecule thiab nws daim iav duab yog enantiomers ntawm ib leeg. Piv txwv li, 2-butanol molecule yog chiral, thiab nws thiab nws cov duab iav yog enantiomers.
Qhov txawv ntawm Isotopes thiab Isomers yog dab tsi?
• Isotopes yog txawv atoms ntawm tib lub caij. Isomers yog cov sib txuas sib txawv nrog tib cov qauv molecular.
• Isotopes txawv ntawm ib leeg vim muaj pes tsawg tus neutrons, qhov isomers txawv ntawm ib leeg vim yog kev npaj ntawm atoms.
• Isotopes ntawm ib lub caij muaj tib yam tshuaj lom neeg tus cwj pwm, tab sis lub cev lub cev yuav txawv. Isomers nrog tib cov tshuaj formula muaj qhov sib txawv ntawm cov tshuaj thiab lub cev (tshwj tsis yog qee cov isomers).
