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Radioactivity

Q- Kr-85 is a radioactive isotope that is used in measuring paper thickness. It decays by emission with a half-life of 10.8 years

(a) Write down the decay equation showing the daughter isotope and decay products of this process.

(b) A Kr-85 source had activity 30 mCi when new. Estimate its activity after 5 years' use.

(c) What is the activity of a 30 mCi source in becquerels?

(d) What is the mass of Kr-85 in the source when new?

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