Mehlala ea Lipotso tse Buisanang ka ho Bola ha Beta (β)
Ho bola ha mahlaseli a kotsi ke mokhoa oo ka oona nucleus e sa tsitsang ea athomo e lokollang likaroloana ho fihlela boemo bo tsitsitseng haholoanyane. Sehloohong sena, re tla tsepamisa maikutlo ho bola ha beta (β), mofuta oa ho bola ha mahlaseli a kotsi. Sepheo sa rona se seholo ke ho utloisisa ho bola ha beta ka mehlala le litharollo tsa eona. A re qaleng ka ho ithuta metheo ea ho bola ha beta pele re teba mehlala.
Metheo ea ho Bola ha Beta
Ho bola ha beta ho kenyelletsa phetoho ea li-nuclei tse itseng tsa athomo ka ho ntša likaroloana tsa beta. Ho na le mefuta e 'meli ea ho bola ha beta:
1. Ho bola ha Beta-minus (β-): Ho bola hona, neutron e ka har'a nucleus e fetoha proton, elektrone (e tsejoang e le karoloana ea beta), le elektrone antineutrino. Tekanyo ea karabelo ke:
\[
n \ motsu p + e^- + \bareng{\nu}_e
\]
Mona, \( n \) ke neutron, \( p \) ke proton, \( e^- \) ke elektrone (beta), mme \( \bar{\nu}_e \) ke elektrone antineutrino.
2. Ho bola ha Beta-plus (β+): Sena se etsahala ha proton e ka hara nucleus e fetoha neutron, positron (antielectron), le electron neutrino. Tekanyo ke ena:
\[
p \motsu o nepahetseng n + e^+ + \nu_e
\]
Moo \( e^+ \) e leng positron mme \( \nu_e \) e le neutrino ya dielektrone.
Mohlala oa 1: Beta-minus Decay
Potso:
Sekotwana sa carbon-14 (\( ^{14}_{6}\text{C} \)) se feta ho bola ha beta-minus. Fumana dihlahiswa tsa ho bola hona mme o ngole equation ya nyutlelie.
Puisano:
Taba ea pele, re khetholla hore carbon-14 (\( ^{14}_{6}\text{C} \)) e na le nomoro ea athomo ea 6 le palo ea boima ea 14. Ho bola ha beta-minus, e 'ngoe ea li-neutron ka har'a nucleus e fetoha proton. Sena se bolela hore palo ea athomo ea nucleus e eketseha ka yuniti e le 'ngoe, ha palo ea boima e ntse e tšoana.
Mona ke equation ea ho bola ha beta-minus bakeng sa carbon-14:
\[
^{14}_{6}\text{C} \rightarrow ^{14}_{7}\text{N} + e^- + \bar{\nu}_e
\]
Di mana:
– Sehlahisoa sa ho bola ke nitrogen-14 (\( ^{14}_{7}\text{N} \)).
– Dielektrone (\( e^- \)) ke dikarolwana tsa beta tse ntshitsweng.
– \( \bar{\nu}_e \) ke antineutrino ea elektronike eo le eona e ntšoang.
Mohlala oa 2: Beta-plus Decay
Potso:
Sekotwana sa fluorine-18 (\( ^{18}_{9}\text{F} \)) se feta ho bola ha beta-plus. Fumana dihlahiswa tsa ho bola hona mme o ngole equation ya nuclear.
Puisano:
Fluorine-18 (\( ^{18}_{9}\text{F} \)) e na le nomoro ea athomo ea 9 le palo ea boima ea 18. Ho bola ha beta-plus, proton e ka har'a nucleus e fetoha neutron e fokotsang palo ea athomo ka e le 'ngoe, empa palo ea boima e lula e tšoana.
Mona ke equation ea ho bola ha beta-plus bakeng sa fluorine-18:
\[
^{18}_{9}\text{F} \rightarrow ^{18}_{8}\text{O} + e^+ + \nu_e
\]
Di mana:
– Sehlahisoa sa ho bola ke oksijene-18 (\( ^{18}_{8}\text{O} \)).
– Positron (\( e^+ \)) ke karoloana ea beta e ntšoang.
– \( \nu_e \) ke neutrino ea elektronike eo le eona e ntšoang.
Mohlala oa Potso ea 3: Matla a ho Bola
Potso:
Bala matla a lokollotsoeng nakong ea ho bola ha beta-minus haeba isotope strontium-90 (\( ^{90}_{38}\text{Sr} \)) e bola ho ea ho yttrium-90 (\( ^{90}_{39}\text{Y} \)). Boima ba strontium-90 ke 89,907738 u, 'me boima ba yttrium-90 ke 89,907152 u. Boima ba elektrone ke 0,000548 u.
Puisano:
Matla a lokolloang nakong ea ho bola ha beta-minus a ka baloa ho tloha phapang ea boima pakeng tsa lihlahisoa le li-reactant, ebe a fetoloa matla ho sebelisoa equation ea Einstein \( E=mc^2 \).
Phetoho ea boima (\( \Delta m \)) ke phapang lipakeng tsa boima ba pele le boima ba ho qetela, ho kenyeletsoa le boima ba elektrone e ntšitsoeng:
\[
\Delta m = (\text{mass } ^{90}_{38}\text{Sr}) – (\text{mass } ^{90}_{39}\text{Y} + \text{electron mass})
\]
Phetolo ea boleng:
\[
\Delta m = 89,907738 \, \text{u} – (89,907152 \, \text{u} + 0,000548 \, \text{u})
\]
\[
\Delta m = 0,000038 \, \mongolo{u}
\]
Ho fetolela liphetoho tsa boima ho ba matla (1 u = 931.5 MeV/c²):
\[
E = \Delta m \times 931.5 \, \text{MeV/c}^2
\]
\[
E = 0,000038 \, \text{u} \times 931.5 \, \text{MeV}
\]
\[
E \hoo e ka bang 0,03537 \, \text{MeV}
\]
Matla a lokollotsoeng nakong ea ho bola ke hoo e ka bang 0,03537 MeV.
Qetello
Ho bola ha beta ke ketsahalo e khahlang e re thusang ho utloisisa liphetoho tse poteletseng tse ka hlahang ka har'a nuclei ea athomo. Ka ho ithuta ho bola ha beta-minus le beta-plus, re ka khetholla hore na likarolo li fetoha joang ho ba likarolo tse ling le ho bala matla a lokolloang nakong ea ts'ebetso. Ka bothata bona ba mohlala, re fumana temohisiso e tebileng mabapi le matla a amehang ho bola ha mahlaseli a kotsi le bohlokoa ba likhopolo tsa motheo fisiks ea nyutlelie.
