2.E: Atomi, Molekuli, na Ions (Mazoezi)

2.1: Mawazo mapema katika Nadharia ya Atomiki

Katika kuchora zifuatazo, nyanja za kijani zinawakilisha atomi za kipengele fulani. Sehemu za zambarau zinawakilisha atomi za elementi nyingine. Ikiwa nyanja za vipengele tofauti hugusa, ni sehemu ya kitengo kimoja cha kiwanja. Mabadiliko ya kemikali yafuatayo yanayowakilishwa na nyanja hizi yanaweza kukiuka mojawapo ya mawazo ya nadharia ya atomia ya Dalton. Ambayo moja?

Vifaa vya kuanzia vinajumuisha nyanja moja ya kijani na nyanja mbili za zambarau. Bidhaa hizo zinajumuisha nyanja mbili za kijani na nyanja mbili za zambarau. Hii inakiuka postulate Dalton ya kwamba atomi si kuundwa wakati wa mabadiliko ya kemikali, lakini ni tu kusambazwa tena.

Ni postulate ya nadharia Dalton ni sambamba na uchunguzi zifuatazo kuhusu uzito wa reactants na bidhaa? Wakati gramu 100 za carbonate kali ya kalsiamu inapokanzwa, gramu 44 za dioksidi kaboni na gramu 56 za oksidi ya kalsiamu huzalishwa.

Tambua nadharia ya nadharia ya Dalton inayovunjwa na uchunguzi wafuatayo: 59.95% ya sampuli moja ya dioksidi ya titani ni titani; 60.10% ya sampuli tofauti ya dioksidi ya titani ni titani.

Kauli hii inakiuka postulate ya nne ya Dalton: Katika kiwanja kilichopewa, idadi ya atomi za kila aina (na hivyo pia asilimia) huwa na uwiano sawa.

Sampuli za kiwanja X, Y, na Z zinachambuliwa, na matokeo yaliyoonyeshwa hapa.

Kiwanja	Maelezo	Misa ya Carbon	Misa ya Hidrojeni
X	wazi, isiyo na rangi, kioevu na harufu kali	1.776 g	0.148 g
Y	wazi, isiyo na rangi, kioevu na harufu kali	1.974 g	0.329 g
Z	wazi, isiyo na rangi, kioevu na harufu kali	7.812 g	0.651 g

Je, data hizi hutoa mfano (s) wa sheria ya idadi ya uhakika, sheria ya idadi nyingi, wala, au zote mbili? Data hizi zinakuambia nini kuhusu misombo X, Y, na Z?

2.2: Mageuzi ya Nadharia ya Atomiki

Mazoezi

1. Kuwepo kwa isotopi kunakiuka mojawapo ya mawazo ya awali ya nadharia ya atomia ya Dalton. Ambayo moja?
2. Je, elektroni na protoni zinafanana? Je, ni tofauti gani?
3. Je, protoni na nyutroni zinafanana? Je, ni tofauti gani?
4. Kutabiri na kupima tabia ya chembe α kufukuzwa katika “plum pudding” mfano atomi.
   1. Kutabiri njia zilizochukuliwa na chembe α kwamba ni fired katika atomi na Thomson plum pudding muundo mfano. Eleza kwa nini unatarajia chembe α kuchukua njia hizi.
   2. Ikiwa chembe α za nishati ya juu kuliko zile zilizo katika (a) zinafukuzwa kwenye atomi za pudding za plamu, kutabiri jinsi njia zao zitatofautiana na njia za chembe α za chini za nishati. Eleza hoja zako.
   3. Sasa jaribu utabiri wako kutoka (a) na (b). Fungua simulation ya Rutherford Kueneza na uchague kichupo cha “Plum Pudding Atom”. Weka “Nishati ya Alpha Chembe” hadi “min,” na uchague “onyesha athari.” Bonyeza bunduki kuanza kurusha chembe α. Je, hii inafanana na utabiri wako kutoka (a)? Kama si, kueleza kwa nini njia halisi itakuwa kwamba inavyoonekana katika simulation. Piga kifungo cha pause, au “Weka upya Wote.” Weka “Nishati ya Alpha Carticles” hadi “max,” na uanze kurusha chembe α. Je, hii inafanana na utabiri wako kutoka (b)? Kama siyo, kueleza athari za nishati kuongezeka kwenye njia halisi kama inavyoonekana katika simulation.
5. Kutabiri na kupima tabia ya chembe α zilizofukuzwa kwenye mfano wa atomi wa Rutherford.
   1. (a) Kutabiri njia zilizochukuliwa na chembe α zinazofukuzwa kwenye atomi zilizo na muundo wa mfano wa atomi wa Rutherford. Eleza kwa nini unatarajia chembe α kuchukua njia hizi.
   2. (b) Ikiwa chembe α za nishati ya juu kuliko zile zilizo katika (a) zinafukuzwa kwenye atomi za Rutherford, kutabiri jinsi njia zao zitatofautiana na njia za chembe α za chini za nishati. Eleza hoja zako.
   3. (c) Kutabiri jinsi njia zilizochukuliwa na chembe α zitatofautiana kama zinafukuzwa kwenye atomi za Rutherford za elementi zingine isipokuwa dhahabu. Ni sababu gani unatarajia kusababisha tofauti hii katika njia, na kwa nini?
   4. (d) Sasa jaribu utabiri wako kutoka (a), (b), na (c). Fungua simulation ya Rutherford Kueneza na uchague kichupo cha “Rutherford Atom”. Kutokana na ukubwa wa simulizi, ni bora kuanza na kiini kidogo, hivyo chagua “20" kwa protoni na nyutroni zote mbili, “min” kwa nishati, onyesha athari, halafu uanze kurusha chembe α. Je, hii inafanana na utabiri wako kutoka (a)? Kama si, kueleza kwa nini njia halisi itakuwa kwamba inavyoonekana katika simulation. Pumzika au upya upya, weka nishati kwa “max,” na uanze kurusha chembe α. Je, hii inafanana na utabiri wako kutoka (b)? Kama siyo, kueleza athari za nishati kuongezeka kwa njia halisi kama inavyoonekana katika simulation. Pumzika au upya upya, chagua “40" kwa protoni na nyutroni zote mbili, “min” kwa nishati, onyesha athari, na moto mbali. Je, hii inafanana na utabiri wako kutoka (c)? Kama si, kueleza kwa nini njia halisi itakuwa kwamba inavyoonekana katika simulation. Kurudia hili kwa idadi kubwa ya protoni na nyutroni. Ni generalization gani unaweza kufanya kuhusu aina ya atomi na athari kwenye njia ya chembe α? Kuwa wazi na maalum.

Solutions

1 Dalton awali alidhani kwamba atomi zote za elementi fulani zilikuwa na mali zinazofanana, ikiwa ni pamoja na wingi. Hivyo, dhana ya isotopu, ambayo kipengele kina raia tofauti, ilikuwa ukiukwaji wa wazo la awali. Kuhesabu kuwepo kwa isotopu, postulate ya pili ya nadharia yake ya atomia ilibadilishwa ili kusema kwamba atomi za elementi moja lazima ziwe na tabia za kemikali zinazofanana.

2 Wote ni chembe za subatomiki zinazoishi katika kiini cha atomu. Wote wawili wana takriban molekuli sawa. Protoni ni chaji chanya, wakati neutroni ni uncharged.

3 Zote ni chembe za subatomiki zinazoishi katika kiini cha atomu. Wote wawili wana takriban molekuli sawa. Protoni ni chaji chanya, wakati neutroni ni uncharged.

4. (a) Mfano wa pudding ya plum unaonyesha kuwa chaji chanya huenea kwa usawa katika chembe zote, kwa hiyo tunatarajia chembe α kwa (labda) zimepungua kwa kiasi fulani na kupinduliwa kwa chanya, lakini kufuata njia za mstari wa moja kwa moja (yaani, si kupotoshwa) wanapopitia atomi. (b) Chembe za juu za nishati α zitasafiri kwa kasi (na labda zimepungua chini) na pia zitafuata njia za mstari wa moja kwa moja kupitia atomi. (c) Chembe α zilifuata njia za mstari wa moja kwa moja kupitia atomi ya pudding ya plamu. Hakukuwa na kupunguza kasi dhahiri ya chembe α kama zilivyopita katika atomi.

5. (a) Atomu ya Rutherford ina kiini kidogo chenye chaji chanya, hivyo chembe nyingi za α zitapita katika nafasi tupu mbali na kiini na hazipatikani. Vile chembe α zinazopita karibu na kiini zitafutwa kutoka kwenye njia zao kutokana na kupinduliwa kwa chanya. Zaidi ya moja kwa moja kuelekea kiini chembe α zinaongozwa, angle kubwa ya kufuta itakuwa. (b) chembe za juu za nishati α zinazopita karibu na kiini bado zitafutwa, lakini kwa kasi zinasafiri, chini ya angle inayotarajiwa ya kufuta. (c) Kama kiini ni ndogo, chaji chanya ni ndogo na deflections inatarajiwa ni ndogo—wote kwa suala la jinsi karibu chembe α kupita na kiini undeflected na angle ya deflection. Kama kiini ni kubwa, chaji chanya ni kubwa na deflections inatarajiwa ni kubwa-zaidi α chembe itakuwa deflected, na pembe deflection itakuwa kubwa. (d) Njia zinazofuatwa na chembe α zinafanana na utabiri kutoka (a), (b), na (c).

2.3: Muundo wa Atomiki na Ishara

Kwa njia gani isotopi za elementi iliyotolewa ni tofauti kila wakati? Kwa njia gani wao daima ni sawa?

Andika ishara kwa kila ions zifuatazo:

1. (a) ion yenye malipo ya 1+, nambari ya atomiki 55, na namba ya wingi 133
2. (b) ioni yenye elektroni 54, protoni 53, na nyutroni 74
3. (c) ioni yenye namba atomia 15, namba ya molekuli 31, na malipo ya 3
4. (d) ioni yenye elektroni 24, nyutroni 30, na malipo ya 3+

(a) ¹³³ Cs ⁺; (b) ^{127 I-}; (c) ³¹ P ^3; (d) ⁵⁷ Co ³⁺

Andika ishara kwa kila ions zifuatazo:

1. (a) ion yenye malipo ya 3+, elektroni 28, na idadi kubwa ya 71
2. (b) ioni yenye elektroni 36, protoni 35, na nyutroni 45
3. (c) ioni yenye elektroni 86, neutroni 142, na malipo ya 4+
4. (d) ion yenye malipo ya 2+, namba ya atomiki 38, na namba ya molekuli 87

Fungua simulation ya Kujenga Atom na bonyeza icon ya Atom.

1. (a) Chagua moja ya vipengele vya kwanza vya 10 ambavyo ungependa kujenga na kutaja ishara yake.
2. (b) Drag protoni, nyutroni, na elektroni kwenye template atomu kufanya atomu ya elementi yako. Hali ya idadi ya protoni, neutrons, na elektroni katika atomi yako, pamoja na malipo ya wavu na idadi ya molekuli.
3. (c) Bofya kwenye “Net Charge” na “Nambari ya Misa,” angalia majibu yako kwa (b), na urekebishe, ikiwa inahitajika.
4. (d) Kutabiri kama atomi yako itakuwa imara au imara. Hali hoja yako.
5. (e) Angalia sanduku la “Iimara/Imara”. Je, jibu lako kwa (d) sahihi? Ikiwa sio, kwanza utabiri unachoweza kufanya ili kufanya atomi imara ya kipengele chako, na kisha uifanye na uone ikiwa inafanya kazi. Eleza hoja zako.

(a) Kaboni-12, ¹² C; (b) Atomi hii ina protoni sita na nyutroni sita. Kuna elektroni sita katika atomi ¹² C zisizo na upande wowote. Malipo ya wavu ya atomi hiyo ya neutral ni sifuri, na idadi kubwa ni 12. (c) Majibu yaliyotangulia ni sahihi. (d) atomu itakuwa imara kwani C-12 ni isotopu imara ya kaboni. (e) Jibu lililotangulia ni sahihi. Majibu mengine kwa zoezi hili yanawezekana kama elementi tofauti ya isotopu huchaguliwa.

Fungua Simulation Kujenga Atom

(a) Drag protoni, neutroni, na elektroni kwenye template ya atomu ili kutengeneza atomu ya neutral ya oksijeni-16 na kutoa alama ya isotopu kwa atomi hii.

(b) Sasa ongeza elektroni mbili zaidi kufanya ioni na kutoa ishara kwa ion uliyoiumba.

Fungua Simulation Kujenga Atom

(a) Drag protoni, neutroni, na elektroni kwenye template ya atomu ili kutengeneza atomu ya upande wowote ya Lithiamu-6 na kutoa alama ya isotopu kwa atomi hii.

(b) Sasa ondoa elektroni moja kufanya ion na kutoa ishara kwa ion uliyoiumba.

(a) Lithiamu-6 ina protoni tatu, nyutroni tatu, na elektroni tatu. Ishara ya isotopu ni ⁶ Li au\(\ce{^6_3Li}\). (b) ⁶Li⁺ or \(\ce{^6_3Li+}\)

Determine the number of protons, neutrons, and electrons in the following isotopes that are used in medical diagnoses:

(a) atomic number 9, mass number 18, charge of 1−

(b) atomic number 43, mass number 99, charge of 7+

(c) atomic number 53, atomic mass number 131, charge of 1−

(d) atomic number 81, atomic mass number 201, charge of 1+

(e) Name the elements in parts (a), (b), (c), and (d).

The following are properties of isotopes of two elements that are essential in our diet. Determine the number of protons, neutrons and electrons in each and name them.

(a) atomic number 26, mass number 58, charge of 2+

(b) atomic number 53, mass number 127, charge of 1−

(a) Iron, 26 protons, 24 electrons, and 32 neutrons; (b) iodine, 53 protons, 54 electrons, and 74 neutrons

Give the number of protons, electrons, and neutrons in neutral atoms of each of the following isotopes:

(a) \(\ce{^{10}_5B}\)

(b) \(\ce{^{199}_{80}Hg}\)

(c) \(\ce{^{63}_{29}Cu}\)

(d) \(\ce{^{13}_6C}\)

(e) \(\ce{^{77}_{34}Se}\)

Give the number of protons, electrons, and neutrons in neutral atoms of each of the following isotopes:

(a) \(\ce{^7_3Li}\)

(b) \(\ce{^{125}_{52}Te}\)

(c) \(\ce{^{109}_{47}Ag}\)

(d) \(\ce{^{15}_7N}\)

(e) \(\ce{^{31}_{15}P}\)

(a) 3 protons, 3 electrons, 4 neutrons; (b) 52 protons, 52 electrons, 73 neutrons; (c) 47 protons, 47 electrons, 62 neutrons; (d) 7 protons, 7 electrons, 8 neutrons; (e) 15 protons, 15 electrons, 16 neutrons

Click on the site and select the “Mix Isotopes” tab, hide the “Percent Composition” and “Average Atomic Mass” boxes, and then select the element boron.

(a) Write the symbols of the isotopes of boron that are shown as naturally occurring in significant amounts.

(b) Predict the relative amounts (percentages) of these boron isotopes found in nature. Explain the reasoning behind your choice.

(c) Add isotopes to the black box to make a mixture that matches your prediction in (b). You may drag isotopes from their bins or click on “More” and then move the sliders to the appropriate amounts.

(d) Reveal the “Percent Composition” and “Average Atomic Mass” boxes. How well does your mixture match with your prediction? If necessary, adjust the isotope amounts to match your prediction.

(e) Select “Nature’s” mix of isotopes and compare it to your prediction. How well does your prediction compare with the naturally occurring mixture? Explain. If necessary, adjust your amounts to make them match “Nature’s” amounts as closely as possible.

Repeat Exercise using an element that has three naturally occurring isotopes.

Let us use neon as an example. Since there are three isotopes, there is no way to be sure to accurately predict the abundances to make the total of 20.18 amu average atomic mass. Let us guess that the abundances are 9% Ne-22, 91% Ne-20, and only a trace of Ne-21. The average mass would be 20.18 amu. Checking the nature’s mix of isotopes shows that the abundances are 90.48% Ne-20, 9.25% Ne-22, and 0.27% Ne-21, so our guessed amounts have to be slightly adjusted.

An element has the following natural abundances and isotopic masses: 90.92% abundance with 19.99 amu, 0.26% abundance with 20.99 amu, and 8.82% abundance with 21.99 amu. Calculate the average atomic mass of this element.

Average atomic masses listed by IUPAC are based on a study of experimental results. Bromine has two isotopes ⁷⁹Br and ⁸¹Br, whose masses (78.9183 and 80.9163 amu) and abundances (50.69% and 49.31%) were determined in earlier experiments. Calculate the average atomic mass of bromine based on these experiments.

79.904 amu

Variations in average atomic mass may be observed for elements obtained from different sources. Lithium provides an example of this. The isotopic composition of lithium from naturally occurring minerals is 7.5% ⁶Li and 92.5% ⁷Li, which have masses of 6.01512 amu and 7.01600 amu, respectively. A commercial source of lithium, recycled from a military source, was 3.75% ⁶Li (and the rest ⁷Li). Calculate the average atomic mass values for each of these two sources.

The average atomic masses of some elements may vary, depending upon the sources of their ores. Naturally occurring boron consists of two isotopes with accurately known masses (¹⁰B, 10.0129 amu and ¹¹B, 11.0931 amu). The actual atomic mass of boron can vary from 10.807 to 10.819, depending on whether the mineral source is from Turkey or the United States. Calculate the percent abundances leading to the two values of the average atomic masses of boron from these two countries.

Turkey source: 0.2649 (of 10.0129 amu isotope); US source: 0.2537 (of 10.0129 amu isotope)

The ¹⁸O:¹⁶O abundance ratio in some meteorites is greater than that used to calculate the average atomic mass of oxygen on earth. Is the average mass of an oxygen atom in these meteorites greater than, less than, or equal to that of a terrestrial oxygen atom?

2.4: Chemical Formulas

Explain why the symbol for an atom of the element oxygen and the formula for a molecule of oxygen differ.

The symbol for the element oxygen, O, represents both the element and one atom of oxygen. A molecule of oxygen, O₂, contains two oxygen atoms; the subscript 2 in the formula must be used to distinguish the diatomic molecule from two single oxygen atoms.

Explain why the symbol for the element sulfur and the formula for a molecule of sulfur differ.

Write the molecular and empirical formulas of the following compounds:

(a)

(b)

(c)

(d)

(a) CO Masi ₂, CO empirical ₂; (b) Masi C ₂ H ₂, CH empirical; (c) Masi C ₂ H ₄, upimaji CH ₂; (d) Masi H ₂ SO ₄, empirical H ₂ SO ₄

Andika kanuni za Masi na za maandishi ya misombo ifuatayo:

(a)

(b)

(c)

(d)

Kuamua formula za maandishi kwa misombo yafuatayo:

1. (a) caffeine, C ₈ H ₁₀ N ₄ O ₂
2. (b) fructose, C ₁₂ H ₂₂ O ₁₁
3. (c) peroxide ya hidrojeni, H ₂ O ₂
4. (d) glucose, C ₆ H ₁₂ O ₆
5. (e) asidi ascorbic (vitamini C), C ₆ H ₈ O ₆

(a) C ₄ H ₅ N ₂ O; (b) C ₁₂ H ₂₂ O ₁₁; (c) HO; (d) CH ₂ O; (e) C ₃ H ₄ O ₃

Kuamua formula za maandishi kwa misombo yafuatayo:

1. (a) asidi asidi, C ₂ H ₄ O ₂
2. (b) asidi citric, C ₆ H ₈ O ₇
3. (c) hydrazine, N ₂ H ₄
4. (d) nikotini, C ₁₀ H ₁₄ N ₂
5. (e) butane, C ₄ H ₁₀

Andika kanuni za maandishi kwa misombo ifuatayo:

(a)

(b)

(a) CH ₂ O; (b) C ₂ H ₄ O

Fungua Kujenga simulation ya Molekuli na chagua kichupo cha “Molekuli Kubwa”. Chagua atomi sahihi “Kit” kujenga molekuli yenye atomi mbili za kaboni na sita za hidrojeni. Drag atomi katika nafasi juu ya “Kit” kufanya molekuli. Jina litaonekana wakati umefanya molekuli halisi iliyopo (hata kama sio unayotaka). Unaweza kutumia chombo cha mkasi kutenganisha atomi ikiwa ungependa kubadilisha uhusiano. Bofya kwenye “3D” ili uone molekuli, na uangalie uwezekano wa kujaza nafasi na mpira-na-fimbo.

1. (a) Chora formula ya miundo ya molekuli hii na ueleze jina lake.
2. (b) Je, unaweza kupanga atomi hizi kwa njia yoyote ya kufanya kiwanja tofauti?

Matumizi Kujenga simulation Molekuli kurudia Zoezi, lakini kujenga molekuli na kaboni mbili, hidrojeni sita, na oksijeni moja.

1. (a) Chora formula ya miundo ya molekuli hii na ueleze jina lake.
2. (b) Je, unaweza kupanga atomi hizi kufanya molekuli tofauti? Ikiwa ndivyo, futa formula yake ya kimuundo na ueleze jina lake.
3. (c) Je, molekuli hutolewa katika (a) na (b) sawa? Je, wao hutofautianaje? Wanaitwa nini (aina ya uhusiano kati ya molekuli hizi, si majina yao).

(a) ethanol

(b) methoxymethane, inayojulikana zaidi kama dimethyl ether

(c) Molekuli hizi zina kemikali sawa (aina na idadi ya atomi) lakini miundo tofauti ya kemikali. Wao ni isoma za kimuundo.

Matumizi Kujenga Masimulizi Molekuli kurudia Zoezi, lakini kujenga molekuli na carbons tatu, hidrojeni saba, na klorini moja.

1. Chora formula ya miundo ya molekuli hii na ueleze jina lake.
2. Je, unaweza kupanga atomi hizi kufanya molekuli tofauti? Ikiwa ndivyo, futa formula yake ya kimuundo na ueleze jina lake.
3. Je, molekuli hutolewa katika (a) na (b) sawa? Je, wao hutofautianaje? Wanaitwa nini (aina ya uhusiano kati ya molekuli hizi, si majina yao)?

2.5: Jedwali la Mara kwa mara

Kutumia meza ya mara kwa mara, weka kila moja ya vipengele vifuatavyo kama chuma au nonmetal, na kisha uainishe kila mmoja kama kipengele kikundi kikuu (mwakilishi), chuma cha mpito, au chuma cha ndani cha mpito:

1. urani
2. bromini
3. stronti
4. neon
5. dhahabu
6. americium
7. rhodium
8. salfa
9. kaboni
10. potasiamu

(a) chuma, chuma cha mpito cha ndani; (b) nonmetal, kipengele cha mwakilishi; (c) chuma, kipengele cha mwakilishi; (d) nonmetal, kipengele cha mwakilishi; (e) chuma, chuma cha mpito; (f) chuma, chuma cha mpito; (h) nonmetal, kipengele cha mwakilishi; (i) nonmetal, kipengele cha mwakilishi; (j) chuma, kipengele cha mwakilishi

Kutumia meza ya mara kwa mara, weka kila moja ya vipengele vifuatavyo kama chuma au nonmetal, na kisha uainishe kila mmoja kama kipengele kikundi kikuu (mwakilishi), chuma cha mpito, au chuma cha ndani cha mpito:

1. (a) cobalt
2. (b) europium
3. (c) iodini
4. (d) indiamu
5. (e) lithiamu
6. (f) oksijeni
7. (g) cadmium
8. (h) terbium
9. (i) rhenium

Kutumia meza ya mara kwa mara, tambua mwanachama nyepesi zaidi wa kila makundi yafuatayo:

1. (a) gesi nzuri
2. (b) metali za alkali za ardhi
3. (c) metali za alkali
4. (d) chalcogens

(a) Yeye; (b) Kuwa; (c) Li; (d) O

Kutumia meza ya mara kwa mara, tambua mwanachama mzito zaidi wa kila makundi yafuatayo:

1. (a) metali za alkali
2. (b) chalcogens
3. (c) gesi nzuri
4. (d) metali za ardhi za alkali

1. Tumia meza ya mara kwa mara ili kutoa jina na ishara kwa kila moja ya vipengele vifuatavyo:
2. (a) gesi vyeo katika kipindi kama hicho kama germanium
3. (b) chuma alkali duniani katika kipindi kama hicho kama seleniamu
4. (c) halogen katika kipindi kama hicho kama lithiamu
5. (d) chalcogen katika kipindi hicho kama cadmium

(a) krypton, Kr; (b) kalsiamu, Ca; (c) fluorine, F; (d) tellurium, Te

Tumia meza ya mara kwa mara ili kutoa jina na ishara kwa kila moja ya vipengele vifuatavyo:

1. (a) halogen katika kipindi hicho kama chuma cha alkali na protoni 11
2. (b) chuma cha alkali duniani katika kipindi hicho na gesi ya neutral yenye heshima na elektroni 18
3. (c) gesi yenye sifa nzuri katika mstari sawa na isotopu yenye nyutroni 30 na protoni 25
4. (d) gesi vyeo katika kipindi kama hicho kama dhahabu

Andika ishara kwa kila moja ya isotopu zisizo na upande wowote zifuatazo. Jumuisha nambari ya atomiki na namba ya wingi kwa kila mmoja.

1. (a) chuma cha alkali na protoni 11 na idadi kubwa ya 23
2. (b) elementi ya gesi yenye sifa nzuri na nyutroni 75 katika kiini chake na elektroni 54 katika atomi ya upande wowote
3. (c) isotopi yenye protoni 33 na nyutroni 40 katika kiini chake
4. (d) metali ya alkali ya ardhi yenye elektroni 88 na nyutroni 138

(a)\(\ce{^{23}_{11}Na}\); (b) \(\ce{^{129}_{54}Xe}\); (c) \(\ce{^{73}_{33}As}\); (d) \(\ce{^{226}_{88}Ra}\)

Write a symbol for each of the following neutral isotopes. Include the atomic number and mass number for each.

1. (a) the chalcogen with a mass number of 125
2. (b) the halogen whose longest-lived isotope is radioactive
3. (c) the noble gas, used in lighting, with 10 electrons and 10 neutrons
4. (d) the lightest alkali metal with three neutrons

2.6: Molecular and Ionic Compounds

Using the periodic table, predict whether the following chlorides are ionic or covalent: KCl, NCl₃, ICl, MgCl₂, PCl₅, and CCl₄.

Ionic: KCl, MgCl₂; Covalent: NCl₃, ICl, PCl₅, CCl₄

Using the periodic table, predict whether the following chlorides are ionic or covalent: SiCl₄, PCl₃, CaCl₂, CsCl, CuCl₂, and CrCl₃.

For each of the following compounds, state whether it is ionic or covalent. If it is ionic, write the symbols for the ions involved:

1. (a) NF₃
2. (b) BaO,
3. (c) (NH₄)₂CO₃
4. (d) Sr(H₂PO₄)₂
5. (e) IBr
6. (f) Na₂O

(a) covalent; (b) ionic, Ba²⁺, O²⁻; (c) ionic, \(\ce{NH4+}\), \(\ce{CO3^2-}\); (d) ionic, Sr²⁺, \(\ce{H2PO4-}\); (e) covalent; (f) ionic, Na⁺, O²⁻

For each of the following compounds, state whether it is ionic or covalent, and if it is ionic, write the symbols for the ions involved:

1. (a) KClO₄
2. (b) MgC₂H₃O₂
3. (c) H₂S
4. (d) Ag₂S
5. (e) N₂Cl₄
6. (f) Co(NO₃)₂

For each of the following pairs of ions, write the symbol for the formula of the compound they will form:

1. (a) Ca²⁺, S²⁻
2. (b) \(\ce{NH4+}\), \(\ce{SO4^2-}\)
3. (c) Al³⁺, Br⁻
4. (d) Na⁺, \(\ce{HPO4^2-}\)
5. (e) Mg²⁺, \(\ce{PO4^3-}\)

(a) CaS; (b) (NH₄)₂CO₃; (c) AlBr₃; (d) Na₂HPO₄; (e) Mg₃ (PO₄)₂

For each of the following pairs of ions, write the symbol for the formula of the compound they will form:

1. (a) K⁺, O²⁻
2. (b) \(\ce{NH4+}\), \(\ce{PO4^3-}\)
3. (c) Al³⁺, O²⁻
4. (d) Na⁺, \(\ce{CO3^2-}\)
5. (e) Ba²⁺, \(\ce{PO4^3-}\)

2.7: Chemical Nomenclature

Name the following compounds:

1. (a) CsCl
2. (b) BaO
3. (c) K₂S
4. (d) BeCl₂
5. (e) HBr
6. (f) AlF₃

(a) cesium chloride; (b) barium oxide; (c) potassium sulfide; (d) beryllium chloride; (e) hydrogen bromide; (f) aluminum fluoride

Name the following compounds:

1. (a) NaF
2. (b) Rb₂O
3. (c) BCl₃
4. (d) H₂Se
5. (e) P₄O₆
6. (f) ICl₃

Write the formulas of the following compounds:

1. (a) rubidium bromide
2. (b) magnesium selenide
3. (c) sodium oxide
4. (d) calcium chloride
5. (e) hydrogen fluoride
6. (f) gallium phosphide
7. (g) aluminum bromide
8. (h) ammonium sulfate

(a) RbBr; (b) MgSe; (c) Na₂O; (d) CaCl₂; (e) HF; (f) GaP; (g) AlBr₃; (h) (NH₄)₂SO₄

Write the formulas of the following compounds:

1. (a) lithium carbonate
2. (b) sodium perchlorate
3. (c) barium hydroxide
4. (d) ammonium carbonate
5. (e) sulfuric acid
6. (f) calcium acetate
7. (g) magnesium phosphate
8. (h) sodium sulfite

Write the formulas of the following compounds:

1. (a) chlorine dioxide
2. (b) dinitrogen tetraoxide
3. (c) potassium phosphide
4. (d) silver(I) sulfide
5. (e) aluminum nitride
6. (f) silicon dioxide

(a) ClO₂; (b) N₂O₄; (c) K₃P; (d) Ag₂S; (e) AlN; (f) SiO₂

Write the formulas of the following compounds:

1. (a) barium chloride
2. (b) magnesium nitride
3. (c) sulfur dioxide
4. (d) nitrogen trichloride
5. (e) dinitrogen trioxide
6. (f) tin(IV) chloride

Each of the following compounds contains a metal that can exhibit more than one ionic charge. Name these compounds:

1. (a) Cr₂O₃
2. (b) FeCl₂
3. (c) CrO₃
4. (d) TiCl₄
5. (e) CoO
6. (f) MoS₂

(a) chromium(III) oxide; (b) iron(II) chloride; (c) chromium(VI) oxide; (d) titanium(IV) chloride; (e) cobalt(II) oxide; (f) molybdenum(IV) sulfide

Each of the following compounds contains a metal that can exhibit more than one ionic charge. Name these compounds:

1. (a) NiCO₃
2. (b) MoO₃
3. (c) Co(NO₃)₂
4. (d) V₂O₅
5. (e) MnO₂
6. (f) Fe₂O₃

The following ionic compounds are found in common household products. Write the formulas for each compound:

1. (a) potassium phosphate
2. (b) copper(II) sulfate
3. (c) calcium chloride
4. (d) titanium dioxide
5. (e) ammonium nitrate
6. (f) sodium bisulfate (the common name for sodium hydrogen sulfate)

(a) K₃PO₄; (b) CuSO₄; (c) CaCl₂; (d) TiO₂; (e) NH₄NO₃; (f) NaHSO₄

The following ionic compounds are found in common household products. Name each of the compounds:

1. (a) Ca(H₂PO₄)₂
2. (b) FeSO₄
3. (c) CaCO₃
4. (d) MgO
5. (e) NaNO₂
6. (f) KI

What are the IUPAC names of the following compounds?

1. (a) manganese dioxide
2. (b) mercurous chloride (Hg₂Cl₂)
3. (c) ferric nitrate [Fe(NO₃)₃]
4. (d) titanium tetrachloride
5. (e) cupric bromide (CuBr₂)

(a) manganese(IV) oxide; (b) mercury(I) chloride; (c) iron(III) nitrate; (d) titanium(IV) chloride; (e) copper(II) bromide