Nuclear Processes Key 2020

Nuclear Processes Name K-L-Url HLD O Objective: Distinguish between fission, fusion, and radioactive decay (Obj 4). ^ Part A: Alpha Decay Start by opening the PhET model “Alpha Decay". Make sure that you first start by clicking on the single atom tab . 1. Observe the decay of Po-211. Write a nuclear equation for the decay of Polonium-211. ?0 ^ ^ 4 ^Ar _ c\r VtcU nucleus) 2. What has to happen within the nucleus in order for an atom of Polonium-211 to decay? WYC -tA -ecVr cc -porc-e- YV\ USV overcome Vl/C STVD \ fbre , vesulri / ) V\ release ^ ^ ~ ^ parVtd^) o Helium nucleus The half -life of Po-211 is approximately 500 ms (half a second). Without using the PhET model , sketch a pie graph the number of undecayed Po-211 atoms for a reaction starting with 100 total atom,s. indicating Pb Bo-J * * ° ' So oh* 5/ 5 0 1 . 1 § il a ' «b ^y ^ fc -dU A n5 -/ ^ . / 8T - 5 / 50 / t= 0.5s 1.0 s t= t=1.5s t=2s Now, simulate the decay of 100 Po-211 atoms by adding 100 atoms from the “Bucket o’ Polonium”. Sketch what the pie graph looks like at the times shown. lo * 15 £4 & CtVoVYy ^ A°\ aVo’mS 3. 50 t= 0.5s t=1.0s otVcrviS 2^ cwrvK t=1.5s ^2, t=2s Compare your prediction to the results that you observed. How can you explain any discrepancies? freHij close l rA eruj .5 Sec , ecetn orforv W\s cx 5 o7 chance oV deccujiney bus4 lthe u hcn LJOU £l p a CCM A- , LJOU 4ov 4- diA> C atf headspjtfils go /, / ) of Vk Vi ^ . ' ) \ ' \ ai ^ \e ^v\ - * 4. Is it reasonable to assume that if you start with 10 atoms of Polonium, that 0.5s later only 5 will remain undecayed? What if you start with 500 atoms? Explain. W \ s c\ o\ uoa r -cc\ SovY?b( d tc-Woyi -Vnovc h -YheoOeVvcal W \C&c U opCfuvic v& ^ ai - ^ + 1AC Part B: Beta Decay ( »YMVI U Open the “Beta Decay” PhET model. Make sure that you click on the “Single Atom” tab. 5. Observe the beta decay in the PhET model. Write a nuclear equation for the process. 3> W 6. v • 0. I " - ,-e \ Sav^e -Ww (\ *\ When an atom undergoes beta decay, where does the -beta particle come from? What other particle is produced in this process? * \ v\ &e\-a (- ) ^ CKY\ a - \s > O- fteuVoyt [ M-D jpvolm , Part C: Nuclear Fission Open the "Nuclear Fission" PhET model. Make sure that you click on the “Fission: One Nucleus” tab. 7. Briefly describe the process by which Uranium-235 can be made unstable. Write a nuclear equation for the process. UrAmum Ucorws uns+aUe Vf o-e. eofYyes lAr^\ urv\ - io . 53 S U + 8. 'n u U;1ACV\ & vxeu-VroiA is -fired vV - ^ =9 Suppose that you have 100 atoms of Uranium-235 and you fire a neutron into a single atom. Sketch a qualitative graph of Fissioned U- 235 Atoms vs. Time. U- S 3 6 \Voms iO \ \ Mc B Using the “Chain Reaction” tab within the model, validate your prediction from question? ^ 9. Explain how the PhET model validates/invalidates your prediction made in question Y citing specific \ observations. . TW 9(rve4 Valickfcs Mij ' prtd \ c\rtz>v\ Each. -fisstow f-eachtM. fetectses: 3 neuVrovis Wn sWE c\ £! ssit> w v -eachov^ IA a tAvver 3 U.- 329, ^ Auckt , uWvm^rMij cv\ u W \-Ky VT " ^^ " ' ^ ) ' 10. Using the “Chain Reaction" tab, determine the criteria and settings needed to create an atomic bomb. UA ^ VW o 'r ey Vo ^ bl ' ^ -e d 'cea e CUA ctVofYMe ^ Wave. CVY^ \JO \ fvyxWval awV e &eW vwcWus.u\ os4 yeWasc iss * o A leas-V { v eUVvt ^ Vo s ^sitx A. VV\ £ CWVA. y adion . ^ ' " ^ ^ ' Cx ^ ly) W ) ' vvvvS l '' ^ 11. Explain why “weapons-grade” Uranium would not likely contain very much Uranium-238. U ' ^3%Lav absorb A. vhsVataW. \ VW heuVvov\ ^ /0 \ taeCoy\MA 12 . Use the “Nuclear Reactor” tab to determine the purpose of control rods within a nuclear fission reactor. The control rock we aUe Vo elu absorb sow ert \V\ ? vAe Av& yVS produced tA Hue P\ S5 l 0lA- T-QacffOioS * 5b doe 5 V\ cV procWc - ~S~OD fvxuck * ^ \/ * ^' * ^ 13. Are the following videosfVideo A. Video B) good analogies of nuclear fission? If we were to use mousetraps and ping-pong balls to illustrate fission, what would each represent? Is there anything missing from this model? —^ ^AouseVrap ~^ VA ' l A Hv ' Y\ emVvDv\ _ 935 (UASWWU kViouse -W-ap w» odei wer-e- SoV o{P . , iV is koTop-e) possible. +WV oll \Mt