Chemical Forums
Specialty Chemistry Forums => Nuclear Chemistry and Radiochemistry Forum => Topic started by: mjfranklin on September 23, 2006, 08:15:46 PM
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The homework question reads:
"Use the semiempirical mass equation to compute, for given A, the relation between Z and N for a nucleus that has Sn=0 (the neutron "drip line"). Compute N/Z for A=100."
Using Sn=Btot(A,Z) - Btot(A-1,Z), I have been trying to manipulate the equation so that I can plug in A=N+Z for one of the A values to get N/Z=some A dependent expression. I and several other students have spent hours manipulating the equation every way we can think of, and nothing looks even close to useful for getting an N/Z relationship.
Are we missing something?
Any suggestions would be really appreciated.
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You just need an equation in terms of N's and Z's only. You do not need to manipulate the equation into something that looks like N/Z = blah...blah...
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The N/Z is brought up since we know stable nuclei at around A=100 typically have an N/Z ratio of ~1.3. But, at the neutron drip line the ratio becomes roughly ~1.7. This is the point the problem is subtly trying to make you discover from first princibles.
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Hey, Mitch. I'm also having much trouble with #7 of problem set #3. It gets much messier and longer than I thought. You've worked it out already, right? Could you give us any suggestions for making the math shorter/cleaner? Thanks.
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You just need an equation in terms of N's and Z's only.
You do not need to manipulate the equation into something that looks like N/Z = blah...blah...