Uranium 235 vs Uranium 238
Uranium yog cov hlau hnyav uas muaj nyob hauv lub ntiaj teb cov tub ntxhais kawm. Nws qhov kev tawm tsam nuclear yog qhov laj thawj tseem ceeb los ua kom sov lub ntiaj teb lub hauv paus thiab ua rau muaj qhov tshwm sim zoo li kev sib tw sab av loj. Hauv cov ntawv thov tam sim no, Uranium yog siv rau hauv nuclear reactors thiab tub rog riam phom. Ob qho isotopes ntawm Uranium yog U-235 thiab U-238. Cov isotopes no qhia txog chemistry zoo sib xws tab sis txawv ntawm lub cev thiab kev ua haujlwm nuclear.
Uranium-235
Uranium 235 yog qhov thib ob tshaj plaws isotope thiab ua rau ze li 0.7% ntawm lub ntiaj teb cov ntsiab lus Uranium. Lub nucleus ntawm no muaj 92 protons thiab 143 neutrons: 3 neutrons tsawg dua U-238 uas ua rau nws sib zog me ntsis. Nws ib nrab-lub neej (Lub Sijhawm coj mus rau ib nrab ntawm cov qauv qub los ntawm kev tawg ntawm nuclear) yog ze li ntawm 704 lab xyoo, uas qhia tau hais tias muaj kev cuam tshuam sai dua nuclear los ntawm alpha lwj dua li nws cov phooj ywg isotope. Uranium 235 nkag mus rau hauv fission (tau txais ib lub neutron thiab lub nucleus splitting ua ob). Qhov no muab nws lub peev xwm los pib nuclear fission chain reactions.
Uranium-238
Uranium-238 yog cov isotope ntau tshaj plaws uas muaj txog li 99.3% ntawm lub ntiaj teb cov ntsiab lus Uranium. Lub "238" qhia tias lub nucleus muaj 92 protons thiab 146 neutrons sib sau ua ib pawg ntawm 238. Nws ib nrab-lub neej yog txog 4.5 billion xyoo, uas qhia tau hais tias qeeb heev nuclear kev ua. Nuclear fission cov tshuaj tiv thaiv qeeb qeeb hauv U-238. Txawm li cas los xij, nws muaj peev xwm ntes tau ib qho neutron, ua 2 beta decays thiab dhau los ua Plutonium-239 uas tuaj yeem nkag mus rau fission.
Qhov txawv ntawm Uranium-235 thiab Uranium-238 yog dab tsi?
• Uranium-235 muaj 143 neutrons thiab Uranium-238 muaj 146 neutrons.
• Uranium-235 yog me ntsis sib dua li Uranium-238.
• Uranium-235 tsawg dua thaum piv rau Uranium-238.
• Uranium-235 muaj ib nrab neej luv dua Uranium-238; Yog li ntawd, fission thiab alpha lwj yog qhov zoo dua hauv Uranium-235, piv rau Uranium-238.
• Xav txog nuclear reactivity ntawm thawj cov ntaub ntawv, Uranium-235 yog reactive heev dua Uranium-238.
• Nyob ntawm kev siv hluav taws xob nuclear, Uranium-235 tuaj yeem siv ncaj qha los ua cov roj nuclear, tab sis Uranium-238 tsuas yog siv tau los ntawm kev hloov pauv mus rau Plutonium.
• Uranium-235 suav tias yog "muaj menyuam tsis taus" thiab Uranium-238 yog "fertile" vim tias nws tuaj yeem hloov mus rau Plutonium, lwm yam xov tooj cua.
• Uranium-235 tuaj yeem pib cov tshuaj tiv thaiv fission tab sis Uranium-238 ua tsis tau.
