Cov Qauv Atomic: Lub Hauv Paus ntawm Txhua Yam Khoom
Cov atom yog cov khoom tseem ceeb ntawm cov khoom uas ua rau txhua yam hauv lub ntiaj teb. Kev nkag siab txog cov qauv ntawm atomic yog qhov tseem ceeb hauv chemistry, physics, thiab lwm yam kev tshawb fawb, vim tias atoms yog lub hauv paus rau kev sib cuam tshuam ntawm cov ntsiab lus thiab tsim ntau yam khoom sib txawv. Tsab xov xwm no yuav tham txog cov qauv ntawm lub atom, kev hloov pauv ntawm lub tswv yim atomic thoob plaws keeb kwm ntawm kev tshawb fawb, thiab cov khoom tseem ceeb uas ua rau lub atom.
Keeb Kwm ntawm Lub Tswv Yim Atomic
Lub tswv yim ntawm cov atoms pib hauv tebchaws Greece thaum ub nrog tus kws tshawb fawb Democritus (460–370 BC), uas tau qhia txog lub tswv yim tias cov khoom muaj cov khoom me me, tsis pom hu ua atomos, txhais tau tias "tsis tuaj yeem faib ua ob." Txawm li cas los xij, lub tswv yim no tsis tau txais kev txhawb nqa los ntawm cov pov thawj sim thiab yog kev xav txog kev xav ntau dua.
Lub tswv yim ntawm cov atoms pib raug txiav txim siab hauv kev tshawb fawb hauv xyoo pua 19th thaum John Dalton, tus kws tshawb fawb Askiv, tau tawm tswv yim Daltonian atomic theory. Lub tswv yim no tau hais tias txhua yam khoom yog tsim los ntawm cov atoms uas tsis sib cais, tias txhua lub ntsiab lus muaj tib hom atom, thiab tias cov atoms ntawm cov ntsiab lus sib txawv tuaj yeem sib xyaw ua ke los ua cov sib xyaw. Qhov no yog ib kauj ruam tseem ceeb uas tso lub tswv yim ntawm atoms rau hauv lub ntiaj teb kev tshawb fawb.
Kev Tshawb Pom Cov Electrons thiab Thomson's Atomic Model
Thaum kawg ntawm lub xyoo pua 19th, tus kws tshawb fawb Askiv J.J. Thomson tau tshawb pom cov khoom me me uas tam sim no hu ua electron los ntawm kev sim cathode ray tube. Thomson tau tsim cov qauv plum pudding, piav qhia cov atoms ua cov pob zeb uas muaj hluav taws xob zoo nrog cov electrons tawg thoob plaws, zoo li raisins hauv ib lub ncuav mog qab zib.
Rutherford tus qauv atom
Xyoo 1911, Ernest Rutherford, los ntawm kev sim ua kom cov alpha particles tawg rau ntawm cov ntawv ci kub, tau ua tiav qhia tias cov atoms muaj lub hauv paus me me, ntom ntom, thiab muaj hluav taws xob zoo nyob hauv nruab nrab, uas tom qab ntawd tau hu ua lub nucleus. Cov electrons nyob ib puag ncig lub hauv paus no nrog qhov chaw khoob ntawm lawv, sib piv rau Thomson tus qauv, uas kwv yees qhov kev faib tawm ntawm cov electrons tawg ua ib lub voj voog zoo.
Bohr tus qauv atom
Xyoo 1913, Niels Bohr tau qhia txog tus qauv atomic uas zoo dua hu ua Bohr model. Bohr tau hais tias cov electrons txav mus rau hauv cov orbits tshwj xeeb, lossis "shells," nyob ib puag ncig lub nucleus nrog lub zog tshwj xeeb. Cov electrons tsuas yog txav tau los ntawm ib qho orbit mus rau lwm qhov los ntawm kev nqus lossis tso tawm lub zog hauv daim ntawv ntawm photons. Tus qauv Bohr tau muaj feem cuam tshuam loj heev rau kev txhim kho ntawm quantum theory, txawm hais tias thaum kawg nws pom tias tsis yog qhov tseeb rau txhua yam khoom.
Qauv Quantum Mechanics
Nrog kev txhim kho ntawm quantum mechanics, cov qauv atomic tau dhau los ua qhov nyuaj dua thiab raug dua. Ib qho tseem ceeb tau ua los ntawm Erwin Schrödinger, uas tau qhia txog Schrödinger equation, uas piav qhia txog electrons ua cov haujlwm nthwv dej uas qhia txog qhov muaj feem yuav nyob ntawm qhov chaw tshwj xeeb nyob ib puag ncig lub nucleus, es tsis yog nyob rau hauv ib qho orbit ruaj khov. Tus qauv no, feem ntau hu ua electron huab qauv, piav qhia txog thaj chaw uas cov electrons feem ntau yuav pom, hu ua orbitals.
Cov Cheebtsam Tseem Ceeb ntawm Atoms
Cov atoms muaj peb hom subatomic particles tseem ceeb: protons, neutrons, thiab electrons.
1. Cov Protons:
– Cov protons muaj lub zog zoo thiab nyob hauv lub nucleus atomic. Tus naj npawb ntawm cov protons hauv lub nucleus txiav txim siab hom khoom hauv nqe lus nug. Piv txwv li, ib lub atom uas muaj ib lub proton yog hydrogen, thaum ib lub atom uas muaj rau lub protons yog carbon. Tus naj npawb ntawm cov protons hu ua tus lej atomic.
2. Cov neutron:
– Cov neutrons tsis muaj nqi (neutral) thiab pom muaj nyob rau hauv lub nucleus atomic. Tus naj npawb ntawm cov neutrons hauv lub nucleus tuaj yeem sib txawv ntawm cov isotopes sib txawv ntawm ib lub ntsiab lus. Piv txwv li, carbon-12 muaj 6 neutrons, thaum carbon-14 muaj 8 neutrons. Neutrons pab txhawb rau qhov hnyav atomic tab sis tsis cuam tshuam rau cov khoom siv tshuaj lom neeg ntawm lub ntsiab lus.
3. Cov hluav taws xob:
- Cov electrons muaj lub zog tsis zoo thiab txav mus los ncig lub nucleus hauv orbitals ntawm ntau qib zog. Tus naj npawb ntawm cov electrons hauv ib lub atom nruab nrab yog sib npaug rau tus naj npawb ntawm protons. Cov electrons yog lub luag haujlwm rau cov khoom siv tshuaj lom neeg ntawm cov atoms, vim lawv koom nrog kev tsim cov tshuaj sib txuas thiab cov tshuaj tiv thaiv.
Cov Qauv Atomic thiab Kev Sib Txuas Tshuaj
Cov electrons hauv cov atoms raug muab tso rau hauv cov plhaub zog sib txawv raws li txoj cai Aufbau, txoj cai Hund, thiab txoj cai Pauli exclusion. Cov electrons hauv lub plhaub sab nraud (hu ua valence electrons) muaj feem cuam tshuam rau cov khoom siv tshuaj lom neeg thiab kev ua haujlwm ntawm cov atoms. Cov valence electrons no tuaj yeem hloov pauv lossis sib koom nrog lwm cov atoms los tsim cov tshuaj sib txuas, xws li covalent bonds, ionic bonds, thiab metallic bonds.
1. Cov Kev Sib Koom Tes:
- Tshwm sim thaum ob lub atoms sib koom ib lossis ntau khub ntawm cov electrons valence. Qhov no feem ntau tshwm sim hauv cov organic molecules xws li dej (H2O) thiab methane (CH4).
2. Cov Kev Sib Txuas Ionic:
- Tshwm sim thaum ib lub atom pub ib lossis ntau dua ntawm nws cov electrons valence rau lwm lub atom, ua rau muaj cov ions uas muaj nqi zoo (cations) thiab cov ions uas muaj nqi tsis zoo (anions) uas nyiam ib leeg. Ib qho piv txwv zoo yog ntsev (NaCl), uas muaj cov ions sodium (Na+) thiab chloride (Cl-).
3. Cov Hlau Sib Txuas:
- Tshwm sim thaum cov electrons valence ntab ywj pheej ntawm cov hlau ions uas muaj nqi zoo, ua rau lawv "kov" muaj zog thiab muab cov hlau tshwj xeeb xws li kev ua hluav taws xob thiab malleability.
Isotopes thiab Atomic Mass
Cov isotopes yog cov sib txawv ntawm tib lub ntsiab lus uas muaj cov lej sib txawv ntawm cov neutrons hauv lawv cov nuclei. Piv txwv li, cov isotopes feem ntau ntawm carbon yog carbon-12 (6 protons thiab 6 neutrons) thiab carbon-14 (6 protons thiab 8 neutrons). Lub atomic mass ntawm ib lub ntsiab lus yog qhov nruab nrab ntawm tag nrho nws cov isotopes, ntsuas hauv atomic mass units (amu).
Xaus
Kev nkag siab txog cov qauv ntawm atomic yog qhov tseem ceeb rau kev nkag siab txog cov khoom thiab nws cov kev sib cuam tshuam hauv lub ntiaj teb. Txij li Democritus lub tswv yim thaum ntxov ntawm atom mus rau cov qauv quantum mechanical niaj hnub no, kev txhim kho ntawm kev tshawb fawb txog atomic tau hloov pauv txoj kev uas peb pom lub ntiaj teb. Atoms, nrog rau lawv cov khoom protons, neutrons, thiab electrons, ua rau txhua yam khoom thiab ua lub luag haujlwm tseem ceeb hauv cov tshuaj lom neeg thiab cov khoom ntawm cov khoom. Los ntawm kev tshawb nrhiav tob dua, cov kws tshawb fawb txuas ntxiv tshawb pom ntau ntxiv txog qhov xwm txheej tseem ceeb ntawm lub ntiaj teb, qhib cov hauv kev tshiab hauv kev siv tshuab thiab kev tshawb fawb.
