Lattice vs Crystal
Lattice thiab siv lead ua yog ob lo lus sib koom tes. Ob lo lus no siv sib hloov, tab sis muaj qhov sib txawv me me ntawm ob.
Liab
Lattice yog qhov tshwm sim lej. Hauv chemistry, peb tuaj yeem pom ntau hom ionic thiab covalent lattices. Nws tuaj yeem txhais tau tias yog ib qho khoom, uas muaj qhov kev txiav txim peb-dimensional ntawm cov chav hauv paus. Chav tsev yooj yim tuaj yeem yog atom, molecule lossis ion. Lattices yog cov qauv crystalline nrog cov chav nyob hauv qab no. Thaum ions koom nrog ionic bonds, lawv tsim ionic crystals. Piv txwv li, sodium chloride tuaj yeem noj. Sodium yog ib pawg 1 hlau, yog li tsim ib qho +1 them cation. Chlorine yog ib qho nonmetal thiab muaj peev xwm tsim tau ib qho -1 them anion. Nyob rau hauv lub lattice, txhua sodium ion yog ib puag ncig los ntawm rau chloride ions, thiab txhua chloride ion yog surrounded los ntawm rau sodium ions. Vim tag nrho cov kev nyiam ntawm ions, cov qauv lattice yog ruaj khov dua. Tus naj npawb ntawm ions tam sim no nyob rau hauv lub lattice nws txawv nrog qhov loj ntawm nws. Lub zog lattice lossis enthalpy ntawm lattice yog qhov ntsuas ntawm lub zog ntawm cov ionic bonds hauv cov lattice. Nquag lattice enthalpy yog exothermic.
Pob zeb diamond thiab quartz yog ob qho piv txwv rau peb-dimensional covalent lattices. Pob zeb diamond yog tsim los ntawm tsuas yog carbon atoms, thiab txhua cov pa roj carbon atom yog covalently bonded rau plaub lwm carbon atoms los tsim cov qauv lattice. Yog li ntawd, txhua carbon atom muaj tetrahedral kev npaj. Pob zeb diamond, los ntawm kev tsim cov qauv zoo li no, tau txais kev ruaj ntseg siab. (Pob zeb diamond paub tias yog ib qho ntawm cov khoom muaj zog tshaj plaws.) Quartz lossis silicon dioxide kuj muaj covalent bonds, tab sis lawv nyob nruab nrab ntawm silicon thiab oxygen atoms (lattice ntawm txawv atoms). Ob leeg ntawm cov lattices covalent no muaj qhov melting point siab heev, thiab lawv ua tsis tau hluav taws xob.
Crystal
Crystals yog cov khoom khib nyiab, uas tau txiav txim cov qauv thiab sib luag. Cov atoms, molecules, los yog ions nyob rau hauv crystals yog teem nyob rau hauv ib tug tshwj xeeb yam, yog li muaj ib tug ntev-ntev kev txiav txim. Crystals yog ib txwm tshwm sim nyob rau hauv lub ntiaj teb li loj crystalline pob zeb, xws li quartz, granite. Crystals yog tsim los ntawm cov kab mob muaj sia thiab. Piv txwv li, calcite yog tsim los ntawm mollusks. Muaj dej-raws li crystals nyob rau hauv daim ntawv ntawm daus, dej khov los yog glaciers. Crystals tuaj yeem raug cais raws li lawv lub cev thiab tshuaj lom neeg. Lawv yog covalent crystals (xws li pob zeb diamond), metallic crystals (xws li pyrite), ionic crystals (xws li sodium chloride) thiab molecular crystals (xws li qab zib). Crystals tuaj yeem muaj cov duab sib txawv thiab xim. Crystals muaj cov txiaj ntsig zoo nkauj, thiab ntseeg tau tias muaj cov khoom zoo; yog li no, tib neeg siv lawv los ua cov hniav nyiaj hniav kub.
Qhov txawv ntawm Lattice thiab Crystal yog dab tsi?
• Lattice piav txog cov qauv ntawm cov muaju. Thaum ib pab pawg ntawm cov molecules zoo li npaj txhua chav nyob dua ntawm qhov taw tes lattice, ib qho siv lead ua.
• Hauv cov qauv siv lead ua, muaj cov qauv ntawm kev npaj cov atoms lossis units. Cov qauv no yog nyob rau ntawm cov ntsiab lus ntawm lub lattice. Cov ntsiab lus lattice no tau teem rau hauv peb qhov kev txiav txim.
