Strontium-90 Is a Byproduct in Nuclear Reactors Fueled by the Radioisotope

question 156

Multiple Choice

Strontium-90 is a byproduct in nuclear reactors fueled by the radioisotope uranium-235. The half-life of strontium-90 is 28.8 yr. What percentage of a strontium-90 sample remains after 75.0 yr?

• A)68.1
• B)16.5
• C)7.40
• D)38.4
• E)2.60

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A psychological phenomenon where external rewards can reduce intrinsic motivation for a task, due to the individual attributing their behavior to the reward rather than their own interest.

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