Kafli 7 - Svör við æfingum

Svör við æfingum

7.1 Jónatengi

Róteindirnar í kjarnanum breytast ekki við venjuleg efnahvörf. Aðeins ytri rafeindirnar færast til. Jákvæðar hleðslur myndast þegar rafeindir tapast.

P, I, Cl og O myndu mynda anjónir því þau eru málmleysingjar. Mg, In, Cs, Pb og Co myndu mynda katjónir því þau eru málmar.

(a) P^3–; (b) Mg²⁺; (c) Al³⁺; (d) O^2–; (e) Cl^–; (f) Cs⁺

(a) [Ar]4s²3d¹⁰4p⁶; (b) [Kr]4d¹⁰5s²5p⁶ (c) 1s² (d) [Kr]4d¹⁰; (e) [He]2s²2p⁶; (f) [Ar]3d¹⁰; (g) 1s² (h) [He]2s²2p⁶ (i) [Kr]4d¹⁰5s² (j) [Ar]3d⁷ (k) [Ar]3d⁶, (l) [Ar]3d¹⁰4s²

(a) 1s²2s²2p⁶3s²3p¹; Al³⁺: 1s²2s²2p⁶; (b) 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁵; 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶; (c) 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶5s²; Sr²⁺: 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶; (d) 1s²2s¹; Li⁺: 1s²; (e) 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p³; 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶; (f) 1s²2s²2p⁶3s²3p⁴; 1s²2s²2p⁶3s²3p⁶

7.2 Samgild tengi

NaCl samanstendur af stökum jónum sem raðast í kristalsgrind, ekki samgilt tengdum sameindum.

jónaefni: (b), (d), (e), (g) og (i); samgild: (a), (c), (f), (h), (j) og (k)

(a) Cl; (b) O; (c) O; (d) S; (e) N; (f) P; (g) N

(a) H, C, N, O, F; (b) H, I, Br, Cl, F; (c) H, P, S, O, F; (d) Na, Al, H, P, O; (e) Ba, H, As, N, O

N, O, F og Cl

(a) HF; (b) CO; (c) OH; (d) PCl; (e) NH; (f) PO; (g) CN

7.3 Lewis-tákn og Lewis-myndir

(a) átta rafeindir:

(b) átta rafeindir:

(c) engar rafeindir Be²⁺
(d) átta rafeindir:

(e) engar rafeindir Ga³⁺
(f) engar rafeindir Li⁺
(g) átta rafeindir:

A Lewis dot diagram shows the symbol for arsenic, A s, surrounded by eight dots and a superscripted three negative sign.

A Lewis dot diagram shows the symbol for iodine, I, surrounded by eight dots and a superscripted negative sign.

A Lewis dot diagram shows the symbol for oxygen, O, surrounded by eight dots and a superscripted two negative sign.

A Lewis dot diagram shows the symbol for nitrogen, N, surrounded by eight dots and a superscripted three negative sign.

(a)

(b)

(c)

(d)

(e)

(f)

Two Lewis structures are shown. The left shows the symbol M g with a superscripted two positive sign while the right shows the symbol S surrounded by eight dots and a superscripted two negative sign.

Two Lewis structures are shown. The left shows the symbol A l with a superscripted three positive sign while the right shows the symbol O surrounded by eight dots and a superscripted two negative sign.

Two Lewis structures are shown. The left shows the symbol G a with a superscripted three positive sign while the right shows the symbol C l surrounded by eight dots and a superscripted negative sign.

Two Lewis structures are shown. The left shows the symbol K with a superscripted positive sign while the right shows the symbol O surrounded by eight dots and a superscripted two negative sign.

Two Lewis structures are shown. The left shows the symbol L i with a superscripted positive sign while the right shows the symbol N surrounded by eight dots and a superscripted three negative sign.

Two Lewis structures are shown. The left shows the symbol K with a superscripted positive sign while the right shows the symbol F surrounded by eight dots and a superscripted negative sign.

A Lewis diagram shows two phosphorus atoms triple bonded together each with one lone electron pair.

(a)

Í þessu tilfelli er Lewis myndin ófullnægjandi til að sýna fram á þá staðreynd að tilraunir hafa sýnt tvær óparaðar rafeindir í hverri súrefnissameind.
(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)

(j)

(k)

A Lewis structure shows two oxygen atoms double bonded together, and each has two lone pairs of electrons.

A Lewis structure shows a carbon atom that is single bonded to two hydrogen atoms and double bonded to an oxygen atom. The oxygen atom has two lone pairs of electrons.

A Lewis structure shows an arsenic atom single bonded to three fluorine atoms. Each fluorine atom has a lone pair of electrons.

A Lewis structure shows a nitrogen atom with a lone pair of electrons single bonded to a chlorine atom that has three lone pairs of electrons. The nitrogen is also double bonded to an oxygen which has two lone pairs of electrons.

A Lewis structure shows a silicon atom that is single bonded to four chlorine atoms. Each chlorine atom has three lone pairs of electrons.

A Lewis structure shows an oxygen atom with a lone pair of electrons single bonded to three hydrogen atoms. The structure is surrounded by brackets with a superscripted positive sign.

A Lewis structure shows a nitrogen atom single bonded to four hydrogen atoms. The structure is surrounded by brackets with a superscripted positive sign.

A Lewis structure shows a boron atom single bonded to four fluorine atoms. Each fluorine atom has three lone pairs of electrons. The structure is surrounded by brackets with a superscripted negative sign.

A Lewis structure shows two carbon atoms that are triple bonded together. Each carbon is also single bonded to a hydrogen atom.

A Lewis structure shows a carbon atom that is triple bonded to a nitrogen atom that has one lone pair of electrons. The carbon is also single bonded to a chlorine atom that has three lone pairs of electrons.

A Lewis structure shows two carbon atoms joined with a triple bond. A superscripted 2 positive sign lies to the right of the second carbon.

(a) SeF₆:

(b) XeF₄:

(c) ${{\text{SeCl}}_{3}^{\text{+}}\text{:}}$

(d) Cl₂BBCl₂:

A Lewis structure shows a selenium atom single bonded to six fluorine atoms, each with three lone pairs of electrons.

A Lewis structure shows a xenon atom with two lone pairs of electrons. It is single bonded to four fluorine atoms each with three lone pairs of electrons.

A Lewis structure shows a selenium atom with one lone pair of electrons single bonded to three chlorine atoms each with three lone pairs of electrons. The whole structure is surrounded by brackets.

A Lewis structure shows two boron atoms that are single bonded together. Each is also single bonded to two chlorine atoms that both have three lone pairs of electrons.

Tvær gildisrafeindir á hverja Pb frumeind færast yfir á Cl frumeindir; Pb²⁺ jónin sem myndast hefur 6s² gildishvolfsskipan. Tveimur gildisrafeindum í HCl sameindinni er deilt og hinar sex eru staðsettar á Cl frumeindinni sem rafeindapör.

Two reactions are shown using Lewis structures. The top reaction shows a carbon atom, single bonded to three hydrogen atoms and single bonded to an oxygen atom with two lone pairs of electrons. The oxygen atom is also bonded to a hydrogen atom. This is followed by a plus sign and the number one point five, followed by two oxygen atoms bonded together with a double bond and each with two lone pairs of electrons. A right-facing arrow leads to a carbon atom that is double bonded to two oxygen atoms, each of which has two lone pairs of electrons. This structure is followed by a plus sign, a number two, and a structure made up of an oxygen with two lone pairs of electrons single bonded to two hydrogen atoms. The bottom reaction shows a carbon atom, single bonded to three hydrogen atoms and single bonded to another carbon atom. The second carbon atom is single bonded to two hydrogen atoms and one oxygen atom with two lone pairs of electrons. The oxygen atom is also bonded to a hydrogen atom. This is followed by a plus sign and the number three, followed by two oxygen atoms bonded together with a double bond. Each oxygen atom has two lone pairs of electrons. A right-facing arrow leads to a number two and a carbon atom that is double bonded to two oxygen atoms, each of which has two lone pairs of electrons. This structure is followed by a plus sign, a number three, and a structure made up of an oxygen with two lone pairs of electrons single bonded to two hydrogen atoms.

Two Lewis structures are shown. The left depicts a carbon atom single bonded to four chlorine atoms, each with three lone pairs of electrons. The right shows a carbon atom double bonded to an oxygen atom that has two lone pairs of electrons. The carbon atom is also single bonded to two chlorine atoms, each of which has three lone pairs of electrons.

(a)

(b)

(c)

(d)

(e)

A Lewis structure is shown. A nitrogen atom is single bonded to two hydrogen atoms and a carbon atom. The carbon atom is single bonded to a hydrogen atom and two other carbon atoms. One of these carbon atoms is single bonded to two hydrogen atoms and an oxygen atom. The oxygen atom is bonded to a hydrogen atom. The other carbon is single bonded to two oxygen atoms, one of which is bonded to a hydrogen atom. The oxygen atoms have two lone pairs of electron dots, and the nitrogen atom has one lone pair of electron dots.

A Lewis structure is shown. A nitrogen atom is single bonded to two hydrogen atoms and a carbon atom. The carbon atom is single bonded to an oxygen atom and one nitrogen atom. That nitrogen atom is then single bonded to two hydrogen atoms. The oxygen atom has two lone pairs of electron dots, and the nitrogen atoms have one lone pair of electron dots each.

A Lewis structure is shown. A carbon atom is single bonded to three hydrogen atoms and a carbon atom. The carbon atom is single bonded to an oxygen atom and a third carbon atom. This carbon is then single bonded to two oxygen atoms, one of which is single bonded to a hydrogen atom. Each oxygen atom has two lone pairs of electron dots.

A Lewis hexagonal ring structure is shown. From the top of the ring, three carbon atoms, one nitrogen atom, a carbon atom and a nitrogen atom are single bonded to one another. The top carbon is single bonded to an oxygen, the second and third carbons and the nitrogen atom are each single bonded to a hydrogen atom. The next carbon is single bonded to an oxygen atom and the last nitrogen is single bonded to a hydrogen atom. The oxygen atoms have two lone pairs of electron dots, and the nitrogen atoms have one lone pair of electron dots.

A Lewis structure is shown. A carbon atom is single bonded to three oxygen atoms. Two of those oxygen atoms are each single bonded to a hydrogen atom. Each oxygen atom has two lone pairs of electron dots.

A Lewis structure is shown. A carbon atom is single bonded to three hydrogen atoms and another carbon atom. The second carbon atom is double bonded to another carbon atom and single bonded to a hydrogen atom. The last carbon is single bonded to two hydrogen atoms.

Í hverju efnatengi felst að rafeindum er deilt á milli atóma. Tveimur rafeindum er deilt í eintengi; fjórum rafeindum er deilt í tvítengi; og sex rafeindum er deilt í þrítengi.

7.4 Formlegar hleðslur og vokmyndir

(a)

(b)

(c)

(d)

(e)

Two Lewis structures are shown with a double-headed arrow in between. The left structure shows a sulfur atom with a lone pair of electrons single bonded to the left to an oxygen atom with three lone pairs of electrons. The sulfur atom is also double bonded on the right to an oxygen atom with two lone pairs of electrons. The right structure depicts the same atoms, but this time the double bond is between the left oxygen and the sulfur atom. The lone pairs of electrons have also shifted to account for the change of bond types. The sulfur atom in the right structures, also has a third electron dot below it.

Three Lewis structures are shown, with double-headed arrows in between, each surrounded by brackets and a superscripted two negative sign. The left structure depicts a carbon atom bonded to three oxygen atoms. It is single bonded to two of these oxygen atoms, each of which has three lone pairs of electrons, and double bonded to the third, which has two lone pairs of electrons. The double bond is located between the bottom oxygen and the carbon. The central and right structures are the same as the first, but the position of the double bonded oxygen has moved to the left oxygen in the right structure while the central structure only has single bonds. The lone pairs of electrons change to correspond with the bonds as well.

Two Lewis structures are shown, with a double-headed arrow in between, each surrounded by brackets and a superscripted negative sign. The left structure depicts a carbon atom bonded to three oxygen atoms. It is single bonded to one of these oxygen atoms, which has three lone pairs of electrons, and double bonded to the other two, which have two lone pairs of electrons. One of the double bonded oxygen atoms also has a single bond to a hydrogen atom. The right structure is the same as the first, but there is only one double bonded oxygen. The oxygen with the single bonded hydrogen now has a single bond to the carbon atom. The lone pairs of electrons have also changed to correspond with the bonds.

Two Lewis structures are shown with a double-headed arrow in between. The left structure depicts a hexagonal ring composed of five carbon atoms, each single bonded to a hydrogen atom, and one nitrogen atom that has a lone pair of electrons. The ring has alternating single and double bonds. The right structure is the same as the first, but each double bond has rotated to a new position.

Two Lewis structures are shown with a double-headed arrow in between. The left structure shows a carbon atom single bonded to two hydrogen atoms and a second carbon atom. The second carbon atom is single bonded to a hydrogen atom and double bonded to a third carbon atom. The third carbon atom is single bonded to two hydrogen atoms. The whole structure is surrounded by brackets and a superscripted negative sign. The right structure shows a carbon atom single bonded to two hydrogen atoms and double bonded to a second carbon atom. The second carbon atom is single bonded to a hydrogen atom and a third carbon atom. The third carbon atom is single bonded to two hydrogen atoms. The whole structure is surrounded by brackets and a superscripted negative sign.

A pair of Lewis structures are shown with a double-headed arrow in between the pair. The left structure of the first pair shows a nitrogen atom with one lone pair of electrons single bonded to an oxygen atom with three lone pairs of electrons. It is also double bonded to an oxygen with two lone pairs of electrons. The right image of this pair depicts the mirror image of the left. Both images are surrounded by brackets and a superscripted negative sign. They are labeled, “For N O subscript two superscript negative sign.”

(a)

(b)

CO hefur sterkasta kolefnis-súrefnis efnatengið vegna þess að það er þrítengi sem tengir C og O. CO₂ hefur tvítengi.

This structure shows a carbon atom double bonded to two oxygen atoms, each of which has two lone pairs of electrons.

The right structure of this pair shows a carbon atom with one lone pair of electrons triple bonded to an oxygen with one lone pair of electrons.

(a) H: 0, Cl: 0; (b) C: 0, F: 0; (c) P: 0, Cl 0; (d) P: 0, F: 0

Cl í Cl₂: 0; Cl í BeCl₂: 0; Cl í ClF₅: 0

(a)

(b)

(c)

(d)

Two Lewis structures are shown with a double-headed arrow in between. The left structure shows an oxygen atom with one lone pair of electrons single bonded to an oxygen atom with three lone pairs of electrons. It is also double bonded to an oxygen atom with two lone pairs of electrons. The symbols and numbers below this structure read, “( 0 ), ( positive 1 ), ( negative 1 ).” The phrase, “Formal charge,” and a right-facing arrow lie to the left of this structure. The right structure appears as a mirror image of the left and the symbols and numbers below this structure read, “( negative 1 ), ( positive 1 ), ( 0 ).”

Two Lewis structures are shown, with a double-headed arrow in between. The left structure shows a sulfur atom with one lone pair of electrons single bonded to an oxygen atom with three lone pairs of electrons. The sulfur atom also double bonded to an oxygen atom with two lone pairs of electrons. The symbols and numbers below this structure read, “( negative 1 ), ( positive 1 ), ( 0 ).” The right structure appears as a mirror image of the left and the symbols and numbers below this structure read, “( 0 ), ( positive 1 ), ( negative 1 ).”

[Two Lewis structures are shown, with brackets surrounding each with a superscripted negative sign and a double ended arrow in between. The left structure shows a nitrogen atom with one lone pair of electrons single bonded to an oxygen atom with three lone pairs of electrons and double bonded to an oxygen atom with two lone pairs of electrons. The symbols and numbers below this structure read “open parenthesis, 0, close parenthesis, open parenthesis, 0, close parenthesis, open parenthesis, negative 1, close parenthesis. The right structure appears as a mirror image of the left and the symbols and numbers below this structure read “open parenthesis, negative 1, close parenthesis, open parenthesis, 0, close parenthesis, open parenthesis, 0, close parenthesis.]

[Three Lewis structures are shown, with brackets surrounding each with a superscripted negative sign and a double ended arrow in between. The left structure shows a nitrogen atom single bonded to two oxygen atoms, each with three lone pairs of electrons and double bonded to an oxygen atom with two lone pairs of electrons. The single bonded oxygen atoms are labeled, from the top of the structure and going clockwise, “open parenthesis, negative 1, close parenthesis, open parenthesis, positive 1, close parenthesis”. The symbols and numbers below this structure read “open parenthesis, 0, close parenthesis, open parenthesis, negative 1, close parenthesis. The middle structure shows a nitrogen atom single bonded to two oxygen atoms, each with three lone pairs of electrons, one of which is labeled “open parenthesis, positive 1, close parenthesis” and double bonded to an oxygen atom with two lone pairs of electrons labeled “open parenthesis, 0, close parenthesis”. The symbols and numbers below this structure read “open parenthesis, negative 1, close parenthesis, open parenthesis, negative 1, close parenthesis. The right structure shows a nitrogen atom single bonded to two oxygen atoms, each with three lone pairs of electrons and double bonded to an oxygen atom with two lone pairs of electrons. One of the single bonded oxygen atoms is labeled, “open parenthesis, negative 1, close parenthesis while the double bonded oxygen is labeled, “open parenthesis, positive 1, close parenthesis”. The symbols and numbers below this structure read “open parenthesis, negative 1, close parenthesis” and “open parenthesis, 0, close parenthesis”.]

HOCl

Byggingin sem gefur núll í formlegri hleðslu er í samræmi við raunverulegu bygginguna:

A Lewis structure shows a nitrogen atom with one lone pair of electrons single bonded to two hydrogen atoms and an oxygen atom which has two lone pairs of electrons. The oxygen atom is single bonded to a hydrogen atom.

NF₃;

A Lewis structure shows a nitrogen atom with one lone pair of electrons single bonded to three fluorine atoms, each with three lone pairs of electrons.

A Lewis structure shows a hydrogen atom single bonded to an oxygen atom with two lone pairs of electrons. The oxygen atom is single bonded to a sulfur atom. The sulfur atom is double bonded to two oxygen atoms, each of which have three lone pairs of electrons, and single bonded to an oxygen atom with two lone pairs of electrons. This oxygen atom is single bonded to a hydrogen atom.

7.5 Styrkur jóna- og samgildra tengja

(a) −114 kJ; (b) 30 kJ; (c) −1055 kJ

Meiri tengjaorka er í myndinni til vinstri. Það er stöðugra formið.

$\begin{aligned} \text{HCl}{(g)}\, \longrightarrow \, \frac{1}{2}\, {\text{H}}_{2}(g)+\, \frac{1}{2}\, {\text{Cl}}_{2}(g)\, \text{Δ}{H}_{1}^{^{\circ}}=\text{−Δ}{H}_{{\text{f}{[{\text{HCl}{(g)}}]}}}^{^{\circ}} \\ \frac{1}{2}\, {\text{H}}_{2}(g)\, \longrightarrow \, \text{H}{(g)}\, \text{Δ}{H}_{2}^{^{\circ}}=\text{Δ}{H}_{{\text{f}{[{\text{H}{(g)}}]}}}^{^{\circ}} \\ {\frac{1}{2}\, {{\text{Cl}}}_{2}(g)\, \longrightarrow \, \text{Cl}{(g)}\, \text{Δ}{H}_{3}^{^{\circ}}=\text{Δ}{H}_{{\text{f}{[{\text{Cl}{(g)}}]}}}^{^{\circ}}}¯ \\ \text{HCl}{(g)}\, \longrightarrow \, \text{H}{(g)}+\text{Cl}{(g)}\, \text{Δ}{H}^{^{\circ}}=\text{Δ}{H}_{1}^{^{\circ}}+\text{Δ}{H}_{2}^{^{\circ}}+\text{Δ}{H}_{3}^{^{\circ}} \end{aligned}$
$\begin{aligned} \end{aligned}$

S–F efnatengið í SF₄ er sterkara.

C–C einföldu efnatengin eru lengst.

A Lewis structure is shown. A carbon atom that is single bonded to three hydrogen atoms is bonded to a second carbon atom. The second carbon atom is single bonded to two hydrogen atoms. The second carbon atom is single bonded to a third carbon atom that is triple bonded to a fourth carbon atom and single bonded to a fifth carbon atom. The fifth carbon atom is single bonded to a hydrogen atom and double bonded to a sixth carbon atom that is single bonded to two hydrogen atoms.

(a) Þegar tvær rafeindir eru fjarlægðar úr girðihvolfinu missir Ca-radíusinn ysta orkuhvolfið og fer aftur niður á lægra n = 3 hvolfið, sem hefur mun minni radíus. (b) +2 hleðslan á kalsíum togar súrefnið mun nær samanborið við K og eykur þar með grindarorkuna miðað við jón með minni hleðslu. (c) Að fjarlægja 4s-rafeindina í Ca krefst meiri orku en að fjarlægja 4s-rafeindina í K vegna sterkara aðdráttarkrafts kjarnans og þeirrar aukaorku sem þarf til að rjúfa pörun rafeindanna. Önnur jónunarorka fyrir K krefst þess að rafeind sé fjarlægð af lægra orkuhvolfi, þar sem aðdráttarkraftur kjarnans á rafeindina er mun sterkari. Auk þess þarf orku til að afpara tvær rafeindir á fullu svigrúmi. Fyrir Ca krefst önnur jónunarorkan þess aðeins að stök rafeind sé fjarlægð af óvörðu ytra orkuhvolfinu. (d) Í Al er rafeindin sem fjarlægð er tiltölulega óvarin og ópöruð á p-svigrúmi. Hærri orkan fyrir Mg endurspeglar aðallega afpörun 2s-rafeindarinnar.

(d)

4008 kJ/mól; báðar jónirnar í MgO hafa tvöfalda hleðslu jónanna í LiF; tengilengdin er mjög svipuð og bæði efnin hafa sömu byggingu; búast má við fjórföldun orkunnar miðað við jöfnuna fyrir grindarorku

(a) Na₂O; Na⁺ hefur minni radíus en K⁺; (b) BaS; Ba hefur stærri hleðslu en K; (c) BaS; Ba og S hafa stærri hleðslur; (d) BaS; S hefur stærri hleðslu

(e)

7.6 Sameindabygging og skautun

Staðsetning tveggja setta af ópöruðum rafeindum í vatni neyðir efnatengin til að taka sér ferflötungsfyrirkomulag og HOH-sameindin sem af því hlýst er bogin. HBeH-sameindin (þar sem Be hefur aðeins tvær rafeindir til að tengjast tveimur rafeindum frá vetnunum) verður að hafa rafeindapörin eins langt frá hvort öðru og mögulegt er og er því línuleg.

Það verður að vera pláss fyrir hvert rafeindapar, hvort sem það er í efnatengi eða til staðar sem stök rafeindapör. Rúmfræði rafeindapara tekur tillit til staðsetningar allra rafeinda. Sameindabygging tekur aðeins tillit til rúmfræði tengipara.

Svo lengi sem skautuðu efnatengin vega hvort annað upp (til dæmis ef tvær eins frumeindir eru staðsettar beint á móti hvor annarri miðað við miðfrumeindina) getur sameindin verið óskautuð.

(a) Bæði rafeindapara- og sameindabygging eru áttflötungur. (b) Bæði rafeindapara- og sameindabygging eru þríhyrningslaga tvípýramídi. (c) Bæði rafeindapara- og sameindabygging eru línuleg. (d) Bæði rafeindapara- og sameindabygging eru þríhyrningslaga flöt.

(a) rafeindaparabygging: áttflötungur, sameindabygging: ferningslaga pýramídi; (b) rafeindaparabygging: ferflötungur, sameindabygging: beygð; (c) rafeindaparabygging: áttflötungur, sameindabygging: ferningslaga flatt; (d) rafeindaparabygging: ferflötungur, sameindabygging: þríhyrningslaga pýramídi; (e) rafeindaparabygging: þríhyrningslaga tvípýramídi, sameindabygging: róla; (f) rafeindaparabygging: ferflötungur, sameindabygging: beygð (109°)

(a) rafeindaparabygging: þríhyrningslaga flatt, sameindabygging: beygð (120°); (b) rafeindaparabygging: línuleg, sameindabygging: línuleg; (c) rafeindaparabygging: þríhyrningslaga flatt, sameindabygging: þríhyrningslaga flatt; (d) rafeindaparabygging: ferflötungur, sameindabygging: þríhyrningslaga pýramídi; (e) rafeindaparabygging: ferflötungur, sameindabygging: ferflötungur; (f) rafeindaparabygging: þríhyrningslaga tvípýramídi, sameindabygging: róla; (g) rafeindaparabygging: ferflötungur, sameindabygging: þríhyrningslaga pýramídi

Allar þessar sameindir og jónir innihalda skautuð efnatengi. Aðeins ClF₅, ${{\text{ClO}}_{2}^{\text{−}},}$ PCl₃, SeF₄ og ${{\text{PH}}_{2}^{\text{−}}}$ hafa tvískautavægi.

SeS₂, CCl₂F₂, PCl₃ og ClNO hafa öll tvískautavægi.

P

óskautuð

(a) fjórflötungur; (b) þríhyrningslaga pýramídi; (c) beygður (109°); (d) þríhyrningslaga flatt; (e) beygður (<120°); (f) beygður (109°); (g) CH₃CCH fjórflötungur, CH₃CCH línulegur; (h) fjórflötungur; (i) H₂CCCH₂ línulegur; H₂CCCH₂ þríhyrningslaga flatt

Three Lewis diagrams are shown. The first diagram shows the letter A single bonded to the left and right to the letter B. An example, “C O subscript 2,” and the term, “linear,” are written beside this diagram. The second diagram shows the letter A with two lone pairs of electrons, single bonded to the left and lower right to the letter B. An example, “H subscript 2 O,” and the term, “bent with an approximately 109 degree angle,” are written beside this diagram. The third diagram shows the letter A with one lone electron pair, single bonded to the left and lower right to the letter B. An example, “S O subscript 2,” and the term, “bent with an approximately 120 degree angle,” are written beside this diagram.

(a)

(b)

(c)

(d) ${{\text{CS}}_{3}^{\text{2−}}}$ inniheldur þrjú svæði með rafeindaþéttleika (öll eru efnatengi án stakra rafeindapara); lögunin er þríhyrningslaga flatt; CS₂ hefur aðeins tvö svæði með rafeindaþéttleika (öll efnatengi án stakra rafeindapara); lögunin er línuleg

The figure shows three Lewis structures that are each surrounded by brackets and have a superscripted 2 negative sign. They are written with a double-headed arrow in between each diagram. The first of this trio has a carbon atom single bonded to two sulfur atoms, each of which has thee lone pairs of electrons, and double bonded to a third sulfur atom with two lone pairs of electrons. The second and third diagrams have the same atoms present, but each time the double bond moves between a different carbon and sulfur pair. The lone electron pairs also shift to correspond with the bond changes.

The Lewis structure shows a carbon atom double bonded to two sulfur atoms, each of which has two lone pairs of electrons.

This diagram shows a carbon with one lone electron pair triple bonded to a sulfur with one lone electron pair.

Lewis myndin er gerð úr þremur einingum, en frumeindunum verður að endurraða:

A Lewis structure is shown in which a carbon atom is single bonded to three hydrogen atoms and a second carbon atom. The second carbon is single bonded to a hydrogen atom and double bonded to a third carbon atom which is single bonded to two hydrogen atoms.

Tvískaut sameindarinnar vísar frá vetnisfrumeindunum.

Byggingarnar eru mjög svipaðar. Í líkanhamnum tekur hver rafeindahópur jafn mikið pláss, þannig að tengihornið er sýnt sem 109,5°. Í „raunverulega“ hamnum eru einu rafeindapörin stærri, sem veldur því að vetnin þjappast saman. Þetta leiðir til minna horns, 104,5°.