20170513

Physics quiz question: comparing rate of radioactive decays

Physics 205B Quiz 7, spring semester 2017
Cuesta College, San Luis Obispo, CA

Two samples currently have certain amounts of a radioactive isotope, an embedded gaseous daughter element (which is the byproduct of the radioactive decay process), and inert material (which is not involved in the decay process). In terms of decays per time, __________ is more active.
(A) sample A.
(B) sample B.
(C) (There is a tie.)
(D) (Not enough information is given.)

Correct answer (highlight to unhide): (C)

The rate of radioactive decays per second depends on the amount of radioactive isotopes. Since both samples contain the same amount of the same type of radioactive isotope, then they will have the same rate of decay.

Sections 30882, 30883
Exam code: quiz07N4ci
(A) : 6 students
(B) : 15 students
(C) : 5 students
(D) : 0 students

Success level: 19%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.43

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