Question

An unknown radioactive element decays into non-radioactive substances. In 520 days the radioactivity of a sample...

An unknown radioactive element decays into non-radioactive substances. In 520 days the radioactivity of a sample decreases by 35 percent.

(a) What is the half-life of the element? (days)

(b) How long will it take for a sample of 100 mg to decay to 44 mg? time needed: (days)

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