Small Traces of Radioactive Substances, Mainly from the Food We

question 99

Multiple Choice

Small traces of radioactive substances, mainly from the food we eat, are present in the human body. The most abundant radioisotope in the body is potassium-40. A person weighing 70 kg contains about 150 g of potassium, and about 0.01% of this amount is potassium-40. The half-life of potassium-40 is 1.25 10⁹ years. Estimate the rate at which radiation is produced by the decay of potassium-40 in the body.

• A)4,000 decays/s
• B)40,000 decays/s
• C)400,000 decays/s
• D)400 decays/s
• E)4 decays/s

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Definitions:

Efficiency Problem

An issue or circumstance that prevents an economic system or process from optimizing resource use to achieve the greatest output or utility.

Exclude

To eliminate or leave out from consideration or a group.

Public Good

A good that is non-excludable and non-rivalrous, meaning it can be used by everyone and one person's use does not reduce availability to others.

Market Failure

A scenario where the free market fails to allocate resources efficiently, resulting in negative impacts on social welfare.