  Problem solving tips

## Nuclei

- Want to score better marks in exams? Have a look at some problem solving tips.
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Tip 1: Completing Nuclear Reactions
Predicting reaction products can be an easy task if one knows the reaction pathways. But how can you deduce products/reactants in a reaction if you don't know the reaction pathway. Follow these simple tips to help complete any nuclear reaction.  Complete the following reaction.

................ + Energy
A
B
C
D
None of the above
An atomic nucleus A is composed of protons and neutrons. The nucleus A emits -particle and is transformed into a nucleus B. What is the composition of B ?
A
protons and neutrons
B
protons and neutrons
C
protons and neutrons
D
protons and neutrons
What are the value of and respectively in the reaction
A
B
C
D
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Tip 2: Multiple Decay Problems
In cases where a radioactive nuclide undergoes multiple decays how will you deduce the final product? Lets first tabulate the possible spontaneous decay pathways for a radioactive nuclide.  Let us delineate the changes that happen within a nucleus for each decay scheme.  A nucleus with emits the following in a sequence; . The of the resulting nucleus is :
A
B
C
D
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Tip3: Problems on half-life  How can we determine the amount of radioactive nuclei left in a sample after time t? Let us break down the steps.  A radioactive isotope of mercury, , decays to gold, , with a disintegration constant of . (a) Calculate the half-life of the .What fraction of a sample will remain at the end of (b) three half-lives and (c) 10.0 days?