Isibonelo Semibuzo Yengxoxo Ye-Radioactivity
I-Radioactivity iyinto yemvelo lapho ama-nuclei athile e-athomu ebola khona ngokuzenzakalelayo, ekhulula izinhlayiya noma amandla ngesimo semisebe. Le nto ibangela ukusabela okuhlukahlukene kwesayensi, ubuchwepheshe, ngisho nempilo. I-Radioactivity inezinhlelo zokusebenza ezahlukahlukene, kodwa futhi idinga ukuqonda okujulile ukuze isetshenziswe ngokuphephile nangokuphumelelayo. Kulesi sihloko, sizoxoxa ngezinkinga eziningana zezibonelo ezihlobene ne-radioactivity kanye nezixazululo zazo, ezingakusiza ukuthi uqonde lo mqondo ngokujulile.
Umbuzo 1: Ukubala i-Half-Life
Umbuzo: Isampula enemisebe iqukethe amagremu angu-80 e-isotope ethile enengxenye yokuphila kweminyaka eyi-10. Ingakanani i-isotope esele ngemva kweminyaka engama-30?
Ingxoxo: Isigamu sokuphila yisikhathi esidingekayo ukuze ingxenye yenani lokuqala le-isotope enemisebe ibole. Ukuze sithole inani le-isotope elisele ngemva kwesikhathi esithile, singasebenzisa ifomula yokubola:
\[ N = N_0 \kwesobunxele(\frac{1}{2}\kwesokudla)^{\frac{t}{t_{1/2}}} \]
Di mana:
– \( N \) inani lama-isotope asele.
– \( N_0 \) yinombolo yokuqala yama-isotopes (amagremu angu-80).
– \(t \) yisikhathi esidlulile (iminyaka engama-30).
– \(t_{1/2} \) yisigamu sokuphila (iminyaka eyi-10).
Ukushintshanisa iziguquguquko ngezinombolo ezaziwayo:
\[ N = 80 \kwesobunxele(\frac{1}{2}\kwesokudla)^{\frac{30}{10}} = 80 \kwesobunxele(\frac{1}{2}\kwesokudla)^3 = 80 \izikhathi \frac{1}{8} = 10 \umbhalo{amagremu} \]
Ngakho-ke, ngemva kweminyaka engama-30, kusala amagremu ayi-10 e-isotope.
Umbuzo 2: Ukunquma Umsebenzi Wemisebe
Umbuzo: Uma umsebenzi wokuqala wesampula yemisebe ingu-2000 Bq futhi ngemva kweminyaka emi-5 umsebenzi wayo uba ngu-250 Bq, nquma ukuthi isigamu sempilo yayo.
Ingxoxo: Umsebenzi (\(A\)) wesampula enemisebe ulingana ngqo nenani le-isotope elikhona:
\[ A = A_0 \kwesobunxele(\frac{1}{2}\kwesokudla)^{\frac{t}{t_{1/2}}} \]
Ukusebenzisa ulwazi olunikeziwe:
– Umsebenzi wokuqala (\(A_0\)) = 2000 Bq
– Umsebenzi wamanje (\(A\)) = 250 Bq
– Isikhathi esidlulile (\(t\)) = iminyaka emi-5
Faka izinombolo kufomula:
\[ 250 = 2000 \kwesobunxele(\frac{1}{2}\kwesokudla)^{\frac{5}{t_{1/2}}} \]
\[ \frac{1}{8} = \left(\frac{1}{2}\right)^{\frac{5}{t_{1/2}}} \]
Ukuze sixazulule lesi sibalo, sinquma amandla e-\(\frac{1}{2}\) okuholela ku-\(\frac{1}{8}\). Ngakho-ke, \(\left(\frac{1}{2}\right)^3 = \frac{1}{8}\).
Ngakho-ke, singabhala:
\[ \frac{5}{t_{1/2}} = 3 \]
\[t_{1/2} = \frac{5}{3} \cishe kube ngu-1.67 \umbhalo{iminyaka} \]
Ngakho-ke, isigamu sokuphila kwe-isotope cishe iminyaka eyi-1.67.
Umbuzo 3: Amandla Okubola Okunemisebe
Umbuzo: I-nucleus ye-athomu iyabola ngokukhulula inhlayiya ye-alpha (helion: He) bese ikhulula amandla angu-5 MeV. Bala amandla akhishwe uma amagremu ayi-10 e-nucleus ebola ngokuphelele. Ake sithi i-mole eyodwa yale nucleus iqukethe ama-athomu e-Avogadro angaguquki \(6.022 \times 10^{23}\) ahlala njalo.
Ingxoxo: Okokuqala, sidinga ukuthola ukuthi zingaki ama-athomu kumagremu ayi-10. Uma i-athomu eyodwa ikhipha i-5 MeV, sidinga ukuguqula lokhu kube amandla aphelele awo wonke ama-athomu.
1. Bala inani lama-moles e-nucleus:
– Ake sithi isisindo se-athomu se-nucleus singama-210 (isibonelo se-isotope).
– Ngakho-ke, inani lama-moles kumagremu ayi-10 = \(\frac{10}{210}\) ama-moles.
2. Bala inani lama-athomu:
– Inani lama-athomu = \(\frac{10}{210} \times 6.022 \times 10^{23}\).
3. Bala amandla aphelele:
– Amandla aphelele = Inani lama-athomu \(\izikhathi\) 5 MeV.
– Khumbula ukuguqula i-MeV ibe ama-joule uma kudingeka (1 MeV = \(1.602 \times 10^{-13}\) J).
Ngakho-ke:
Inani lama-athomu = \(\frac{10}{210} \times 6.022 \times 10^{23}\).
Amandla aphelele = \(\left(\frac{10}{210} \times 6.022 \times 10^{23}\right) \times 5 \times 1.602 \times 10^{-13}\) J.
Lokhu kuzonikeza inani eliphelele lamandla abalwe ngama-Joules.
Isiphetho
Ingxoxo engenhla inikeza izibonelo ezivamile zezinkinga ze-radioactivity ezingase zivele ezifundweni ze-nuclear physics. Ukuqonda kahle imiqondo yokubola kwe-radioactive, ukubalwa kwe-half-life, kanye nomsebenzi namandla akhiqizwa ukubola kubalulekile, njengoba lokhu kunemiphumela ebalulekile emikhakheni eyahlukahlukene, okuhlanganisa nezokwelapha (ikakhulukazi ukwelashwa nge-radiotherapy), amandla enuzi, kanye nokuvikelwa kwe-radiation.
Ukuqonda le mibono eyisisekelo nakho kwakha isisekelo sokuhlola ubuchwepheshe besikhathi esizayo obuhilela i-radioactivity, kuyilapho futhi kukhuliswa ukuqwashisa ngokubaluleka kokuphatha izinto ezisebenzisa i-radioactivity ngokuphephile ukuze kuvikelwe impilo yabantu kanye nemvelo. Njengabafundi noma abacwaningi, ikhono lokuxazulula izinkinga ezinjengalezi lingasiza ekusetshenzisweni okwengeziwe kwesayensi kanye nokutholwa okusha.
