A sample of antimony Ar= 121.7 was analyses and was found to consist of 60% 121 Sb and one other isotope. Determine the mass number of the other isotope in the sample of antimony
I know the answer is Sb123 but idk why so please will someone work through it for me x
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halliethestudent
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- 30-10-2015 12:38
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Laurasaur
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- 30-10-2015 12:51
(Original post by halliethestudent)
A sample of antimony Ar= 121.7 was analyses and was found to consist of 60% 121 Sb and one other isotope. Determine the mass number of the other isotope in the sample of antimony
I know the answer is Sb123 but idk why so please will someone work through it for me x
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So if x is the 2nd isotope's mass...and the abundance is out of 100%, and one of the isotopes is 60%, so the other must be 100-60=40%...
121.7=[(121 * 60%) + (x * 40%)]/100
You need to rearrange that to make X the subject.Spoiler:ShowX=[121.7*100-(121*60)]/40
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Updated: October 30, 2015
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