Dab tsi yog atomic orbitals?

2024 Tus sau: Angel Austin | [email protected]. Kawg hloov kho: 2023-12-17 05:28

Hauv chemistry thiab physics, atomic orbitals yog lub luag haujlwm hu ua nthwv dej ua haujlwm uas piav qhia cov yam ntxwv ntawm tsis pub ntau tshaj ob lub electrons nyob ib puag ncig ntawm lub atomic nucleus lossis system ntawm nuclei, xws li hauv cov molecule. Ib qho orbital feem ntau yog piav qhia raws li thaj tsam peb sab hauv uas muaj 95 feem pua ntawm txoj hauv kev los nrhiav ib qho hluav taws xob.

Thaum lub ntiaj teb txav mus ncig lub hnub, nws taug txoj kev hu ua lub orbit. Ib yam li ntawd, ib qho atom tuaj yeem sawv cev raws li cov hluav taws xob ncig hauv lub orbits nyob ib ncig ntawm lub nucleus. Qhov tseeb, tej yam txawv, thiab cov electrons nyob hauv thaj tsam ntawm qhov chaw hu ua atomic orbitals. Chemistry yog cov ntsiab lus nrog cov qauv yooj yim ntawm lub atom los xam cov Schrödinger yoj kab zauv thiab, raws li, txiav txim siab lub xeev ua tau ntawm lub electron.

Orbits thiab orbitals suab zoo ib yam, tab sis lawv muaj lub ntsiab lus sib txawv kiag li. Nws yog ib qho tseem ceeb heev kom nkag siab qhov txawv ntawm lawv.

Yuav tsis tuaj yeem tso saib lub orbits

Txhim kho txoj hauv kev ntawm ib yam dab tsi, koj yuav tsum paub meej tias qhov khoom nyob qhov twgnyob, thiab muaj peev xwm tsim tau qhov twg nws yuav nyob rau hauv ib pliag. Qhov no yog ua tsis tau rau ib tug electron.

Raws li Heisenberg lub hauv paus ntsiab lus tsis meej, nws tsis tuaj yeem paub meej tias qhov twg nyob rau lub sijhawm tam sim no thiab qhov twg nws yuav nyob tom qab. (Qhov tseeb, lub hauv paus ntsiab lus hais tias nws tsis tuaj yeem txiav txim siab ib txhij thiab nrog qhov tseeb tseeb nws lub sijhawm thiab lub sijhawm).

Yog li ntawd, nws tsis tuaj yeem tsim lub orbit ntawm electron nyob ib ncig ntawm lub nucleus. Qhov no puas yog qhov teeb meem loj? Tsis muaj. Yog ib yam dab tsi ua tsis tau, yuav tsum lees txais thiab nrhiav txoj hauv kev nyob ib puag ncig nws.

Hydrogen electron - 1s-orbital

Y Xav tias muaj ib lub atom hydrogen thiab ntawm ib qho chaw nyob rau hauv lub sij hawm txoj hauj lwm ntawm ib tug electron yog graphically imprinted. Tsis ntev tom qab ntawd, cov txheej txheem rov ua dua thiab cov neeg soj ntsuam pom tias cov khoom nyob hauv txoj haujlwm tshiab. Nws tau li cas los ntawm qhov chaw thib ib mus rau qhov thib ob tsis paub.

Yog tias koj txuas ntxiv rau hauv txoj kev no, koj yuav maj mam tsim ib hom 3D daim ntawv qhia ntawm qhov chaw uas yuav ua tau.

Nyob rau hauv cov ntaub ntawv ntawm hydrogen atom, lub electron tuaj yeem nyob qhov twg hauv qhov chaw nyob ib puag ncig lub nucleus. Daim duab qhia txog ntu ntu ntawm qhov chaw kheej kheej no.

95% ntawm lub sijhawm (lossis lwm feem pua, vim tias tsuas yog qhov loj ntawm lub ntiaj teb tuaj yeem muab ib puas feem pua qhov tseeb) cov hluav taws xob yuav nyob hauv thaj tsam yooj yim ntawm qhov chaw, ze txaus rau lub nucleus. Xws li ib cheeb tsam yog hu ua lub orbital. Atomic orbitals yogthaj chaw ntawm qhov chaw uas muaj hluav taws xob nyob.

Nws ua dabtsi? Peb tsis paub, peb tsis tuaj yeem paub, thiab yog li peb tsuas tsis quav ntsej txog qhov teeb meem no! Peb tsuas tuaj yeem hais tias yog ib qho hluav taws xob nyob rau hauv ib qho orbital, ces nws yuav muaj lub zog.

Txhua lub orbital muaj lub npe.

Qhov chaw nyob los ntawm hydrogen electron hu ua 1s-orbital. Chav tsev ntawm no txhais tau hais tias cov particle yog nyob rau theem zog ze tshaj plaws ntawm lub nucleus. S qhia txog cov duab ntawm lub orbit. S-orbitals yog spherically symmetrical txog lub nucleus - yam tsawg kawg nkaus zoo li lub pob hollow ntawm cov khoom ntom ntom nrog lub nucleus ntawm nws qhov chaw.

2s

Lub orbital tom ntej yog 2s. Nws zoo ib yam li 1s, tshwj tsis yog tias lub tshuab hluav taws xob feem ntau yuav nyob deb ntawm lub nucleus. Qhov no yog lub orbital ntawm lub zog thib ob.

Yog tias koj saib ze, koj yuav pom tias ze rau lub nucleus muaj lwm thaj tsam ntawm cov hluav taws xob ntau dua me ntsis ("qhov ntom" yog lwm txoj hauv kev qhia qhov tshwm sim uas cov khoom no muaj nyob rau hauv ib qho chaw).

2s electrons (thiab 3s, 4s, thiab lwm yam) siv qee lub sijhawm lawv nyob ze rau qhov chaw ntawm lub atom tshaj li qhov xav tau. Qhov tshwm sim ntawm qhov no yog qhov txo qis hauv lawv lub zog hauv s-orbitals. Qhov ze ntawm cov electrons mus rau lub nucleus, lawv lub zog qis dua.

3s-, 4s-orbitals (thiab lwm yam) tau nce ntxiv los ntawm qhov nruab nrab ntawm atom.

P-orbitals

Tsis yog txhua tus electrons nyob hauv lub orbitals (qhov tseeb, tsawg heev ntawm lawv ua). Ntawm thawj theem zog, tsuas yog qhov chaw muaj rau lawv yog 1s, ntawm qhov thib ob, 2s thiab 2p ntxiv.

Orbitals ntawm hom no ntau dua li 2 lub npas zoo ib yam, txuas rau ib leeg ntawm lub hauv paus. Daim duab qhia txog ntu ntu ntawm thaj tsam 3-dimensional ntawm qhov chaw. Ib zaug ntxiv, lub orbital tsuas yog qhia thaj chaw nrog 95 feem pua ntawm txoj kev nrhiav ib qho hluav taws xob.

Yog tias peb xav txog lub dav hlau kab rov tav uas hla lub nucleus hauv txoj kev uas ib feem ntawm lub orbit yuav nyob saum lub dav hlau thiab lwm qhov hauv qab nws, ces muaj pes tsawg qhov yuav nrhiav tau ib qho hluav taws xob ntawm lub dav hlau no.. Yog li yuav ua li cas ib qho particle tau txais los ntawm ib feem mus rau lwm qhov yog tias nws tsis tuaj yeem hla lub dav hlau ntawm nucleus? Qhov no yog vim nws yoj xwm.

Tsis zoo li s-, p-orbital muaj ib qho kev taw qhia.

Ntawm ib theem zog, koj tuaj yeem muaj peb qhov sib npaug p-orbitals nyob ntawm txoj cai kaum rau ib leeg. Lawv yog arbitrarily denoted los ntawm cov cim p_x, p_y thiab p_z. Qhov no tau txais kev yooj yim - txhais tau li cas los ntawm X, Y lossis Z cov lus qhia hloov pauv tas li, vim tias lub atom txav mus rau hauv qhov chaw.

P-orbitals ntawm qib ob lub zog hu ua 2p_x, 2p_y thiab 2p_{z. Muaj cov zoo sib xws ntawm cov tom ntej - 3p}x_{, 3p}y_{, 3p}z_{, 4p}x_{, 4p}y_,4pz _{thiab lwm yam.}

Txhua qib, tshwj tsis yog thawj tus, muaj p-orbitals. Nyob rau theem siab dua, "petals" yog elongated ntau dua, nrog rau qhov feem ntau qhov chaw ntawm cov hluav taws xob ntawm qhov deb dua ntawm lub nucleus.

d- thiab f-orbitals

Ntxiv rau qhov s thiab p orbitals, muaj ob pawg ntawm orbitals muaj rau cov hluav taws xob ntawm qib siab zog. Ntawm qhov thib peb, tej zaum yuav muaj tsib d-orbitals (nrog cov duab nyuaj thiab cov npe), nrog rau 3s- thiab 3p-orbitals (3p_x, 3p_{y., 3p}z_{). muaj tag nrho 9 ntawm no.}

Ntawm plaub, nrog rau 4s thiab 4p thiab 4d, 7 ntxiv f-orbitals tshwm sim - 16 tag nrho, kuj muaj nyob rau txhua qib siab dua.

Qhov chaw ntawm electrons hauv orbitals

Ib lub atom tuaj yeem xav tias yog lub tsev zoo nkauj heev (zoo li lub pyramid inverted) nrog lub nucleus nyob rau hauv pem teb thiab ntau chav nyob rau hauv pem teb sab saud nyob ntawm electrons:

• tsuas muaj 1 chav nyob rau hauv pem teb (1s);
• ntawm chav thib ob twb muaj 4 lawm (2s, 2p_x, 2p_y thiab 2p_z);
• nyob rau hauv pem teb peb muaj 9 chav (ib 3s, peb 3p thiab tsib 3d orbitals) thiab lwm yam.

Tab sis cov chav tsis loj heev. Txhua tus ntawm lawv tsuas tuav tau 2 electrons xwb.

Ib txoj hauv kev yooj yim los qhia cov atomic orbits uas cov khoom no nyob hauv yog kos "quantum cells".

Quantum cells

NuclearOrbitals tuaj yeem sawv cev ua squares nrog cov electrons hauv lawv qhia ua xub. Feem ntau, cov xub nce thiab nqis yog siv los qhia tias cov khoom no txawv.

Qhov kev xav tau sib txawv ntawm electrons hauv ib lub atom yog qhov tshwm sim ntawm quantum txoj kev xav. Yog tias lawv nyob hauv qhov sib txawv orbitals, qhov zoo, tab sis yog tias lawv nyob hauv tib lub orbit, ces yuav tsum muaj qee qhov sib txawv ntawm lawv. Quantum txoj kev xav endows hais nrog cov cuab yeej hu ua "spin", uas yog qhov kev taw qhia ntawm cov xub hais txog.

Lub

1s orbital nrog ob lub tshuab hluav taws xob tau pom tias yog ib lub xwmfab nrog ob lub xub taw qhia nce thiab nqis, tab sis nws tseem tuaj yeem sau tau sai dua li 1s ². Nws nyeem "ib s ob", tsis yog "ib s squared". Cov lej hauv cov ntawv sau no yuav tsum tsis txhob totaub. Qhov thib ib yog qib zog, thiab qhov thib ob yog tus naj npawb ntawm cov khoom ntawm ib lub orbital.

Hybridization

Hauv chemistry, hybridization yog lub tswv yim ntawm kev sib xyaw atomic orbitals rau hauv cov hybrid orbitals tshiab uas muaj peev xwm ua khub electrons los ua cov khoom siv tshuaj. Sp hybridization piav qhia txog cov tshuaj sib txuas ntawm cov tebchaw xws li alkynes. Hauv cov qauv no, 2s thiab 2p carbon atomic orbitals sib xyaw ua ob sp orbitals. Acetylene C₂H₂ muaj sp-sp entanglement ntawm ob lub atoms nrog tsim ntawm σ-bond thiab ob qho ntxiv π-bonds.

Atomic orbitals ntawm carbon hauv saturated hydrocarbons muajzoo tib yam hybrid sp³-orbitals zoo li tus dumbbell, ib feem uas loj dua lwm qhov.

Sp²-hybridization zoo ib yam li yav dhau los thiab yog tsim los ntawm kev sib xyaw ib s thiab ob p-orbitals. Piv txwv li, nyob rau hauv ib qho ethylene molecule, peb sp²- thiab ib p-orbital yog tsim.

Atomic orbitals: filling hauv paus ntsiab lus

Kev xav txog kev hloov pauv ntawm ib lub atom mus rau lwm qhov hauv lub sijhawm ntu ntawm cov khoom siv tshuaj, ib tus tuaj yeem tsim cov qauv hluav taws xob ntawm lub atom tom ntej los ntawm kev tso ib qho ntxiv rau hauv lub voj voog tom ntej.

Electrons, ua ntej sau lub zog siab dua, nyob hauv qis dua nyob ze rau lub nucleus. Qhov twg muaj kev xaiv, lawv sau lub orbitals ib tus zuj zus.

Qhov kev txiav txim sau no yog hu ua Hund txoj cai. Nws tsuas yog siv tau thaum lub atomic orbitals muaj lub zog sib npaug, thiab tseem yuav pab txo qis kev cuam tshuam ntawm cov hluav taws xob, ua rau lub atom ruaj khov dua.

Nco ntsoov tias s-orbital ib txwm muaj lub zog tsawg dua p orbital ntawm tib lub zog, yog li tus qub ib txwm sau ua ntej tom kawg.

Dab tsi yog qhov txawv heev yog txoj haujlwm ntawm 3d orbitals. Lawv nyob rau theem siab dua 4s, thiab yog li 4s orbitals sau ua ntej, ua raws li tag nrho cov 3d thiab 4p orbitals.

Qhov tsis meej pem tib yam tshwm sim ntawm qib siab dua nrog ntau qhov sib txuas ntawm nruab nrab. Yog li ntawd, piv txwv li, 4f atomic orbitals tsis tau sau kom txog thaum txhua qhov chaw ntawm lub6s.

Kev paub txog daim ntawv xaj yog lub hauv paus rau kev nkag siab yuav ua li cas piav txog cov qauv hluav taws xob.