Miisaanka kelli Qaraabo - dabeecad u tiro jirka walax kasta

Miisaanno taagoo, sida mass qaaradda, aad u yar. Sidaa darteed, ay la barbardhigo xisaabinta iyadoo la isticmaalayo unit mass qaaradda. Qaraabo miisaanka kelli xarunta - this magnitude jirka, taas oo ah saamiga miisaanka of Britain xarunta si 1/12 ee saamiga atamka carbon. index Tani waxay muujinaysaa in inta jeer ee miisaanka Britain oo dhan in ka badan 1/12 ah oo miisaankiisu Qurub hoose ee carbon iyo, sida wax qiimo qaraabo leedahay aragti lahayn oo waxaa muujinaysaa calaamad of Mr.

Mr (xarunta) = m (xarunta Britain) / 1/12 m (C). Si kastaba ha ahaatee, ku dhaqanka, waxa uu u adeegsanayaa nidaamka kala duwan ee la xisaabinayo qiimaha this. In wuxuu daankii ku waafaqsan, mass qaraabada kelli si siman u qiimo tirada guud ee dadweynaha qaraabo qaaradda (Ar) ee dhammaan waxyaabaha kiimikada taas oo samaysa xarunta sidii ay tirada qayb ka hoose ee element kasta, i.e. Waxaa schematically waxaa loo qori karaa sida soo socota:

Mr (B1xC1y) = x * Ar (B1) + y * Ar (C1).

Si aad si sax ah loo ogaado qiimaha this waa in ay:

1. ogaan formula kiimiko oo ah walaxda ah;
2. Ar si sax ah loo ogaado in miiska D. I. Mendeleeva (si qiimo haddii tirada ka dib markii dhibic ee jajab tobanle waa siman yahay ama uu privyshaet 5, ka dibna kunka unit ee ugu dhow oo dhan ku daray, waayo, tusaale ahaan, Ar (Li) = 6, 941, si ay u xisaabiso isticmaalaya abyoonaha oo waa 7, iyo haddii tirada ka yar tahay 5, ka dibna ku xiran sida in ay jirto a: Ar (K) = 39,098, i.e., qaado 39).
3. marka la xisaabinayo Mr ha iloobin inay tixgeliyaan tirada atamka, i.e., Federation taagan xubno ka ee xarunta.

mass kelli Qaraabo, formula ee kaas oo la schematically kor ku xusan waxay khusaysaa xeryahooda adag. Maxaa yeelay, xisaabinta maalka tiro y fudud ku filan si loo ogaado kaliya mass qaraabada qaaradda miiska wareegsan iyo optionally bateen tirada Qurub hoose. Tusaale ahaan: Mr (P) = Ar (R) = 31 iyo Mr (N ₂₎ = 2 * Ar (N) = 2 * 14 = 18.

Ka fiirso tusaale kale, oo ogaado waxa uu mass qaraabada kelli oo biyo ah - arrin adag. formula The taaban karo oo ah walaxda waa H ₂ O, i.e., waxay ka kooban tahay laba atamka hydrogen iyo mid la eb oxygen. Sidaa darteed, record go'aanka u egtahay sidan oo kale:

Mr (H ₂ O) = 2 * Ar (H) + Ar ( O) = 2 * + 1 = 16 18

Waxaad ku qori kartaa in gaaban, hoos u hadal suugaan. tiradaasi Tani waxay muujinaysaa in Mr 18 jeer ka badan 1/12 ah carbon mass walxaha hoose. Sidoo kale go'aamisay miisaanka kelli qaraabo ah xarunta kasta oo kiimiko, hoos shardi ah in ay caanaha taaban karo loo yaqaan. Laakiin sidoo kale, la isticmaalayo qiimaha this, aad u soo celin kartaa ka kooban oo tayo iyo tiroba walxaha aan la garanayn, in la dhiso content ee nuclides shaqsi. In dhaqanka, waayo go'aan ka soo baxay Mr walax shaqeeya farsamooyinka physico-kiimikada, sida muxaadaro, spectrometry mass, chromatography gaas , iwm Si loo go'aamiyo index this for polymers loo isticmaalo hababka ku salaysan guryaha colligative (lambarka goostay silsilado double, kooxda functional, ku nafwaayay, awoodda jejebinta iftiinka).

Sayidka, dabeecadda qaraabo kelli mass walax kasta oo noqon doona shaqsi isaga. Qiimaha Tani waxaa ka go'an labada fudud oo adag oo xeryahooda, imanba iyo organic. xuduudaheedu ay si gaar ah u muhiim ah ee waxbarasho iyo synthesizing polymers, kuwaas oo guryaha ku xirnaan doontaa tilmaanta ah oo miisaankeedu yahay kelli.