CH 302 1st Edition Lecture 17Outline of Last Lecture I. Types of Nuclear ChangesII. Chemical vs Nuclear ChangesIII. Binding EnergyIV. Isotopic StabilityV. Ionizing RadiationOutline of Current Lecture I. Beta DecayII. Band of StabilityIII. WorksheetIV. Interpreting the GraphV. Half-Life QuestionsCurrent LectureBeta Decay:- If a problem says beta, assume its negative (or an electron)- There are two types of beta though, a positron (positive beta) and an electron (negative beta)Band of Stability:- The further away something is from the band of stability, the less stable it is and the smaller its half life is- Band of stability plots neutrons vs protons- Isotopes want to get to a stable state so they will go through the process of alpha decay, positron, etc to reach that stable stateWorksheet:1. Write a balanced nuclear equation for the alpha decay of Po-210.210Po → 4He + 206Pb2. Experiment involving each student flipping a coin (heads = standing, tails = sitting)Interpreting the Graph:- Not linear- No constant slope- The first event shows the most Po losto There was the most Po at this time, so when you have the most to begin with youalso have the most to lose - The Po initially and finally is related - As the change in number of Po goes down, the amount of Pb increases by that same amountHalf Life Questions:1. Imagine we started with 96 student isotopes. How many 1⁄2 lives would have to pass to get to 6 student isotopes left?4 events because…96/2 =4848/2 = 2424/2 = 1212/2 = 62. If you had 960 student isotopes, how many 1⁄2 lives would have to pass to get 60 student isotopes left?4 events because… 960/2 = 480480/2 = 240240/2 = 120120/2 = 603. P-32 has a half-life of 14 days. After 3 months what would be the residual radioactivity of 1 millicurie of ATP labeled with P-32?15.625 microcuries because 3 months is about 6 half
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