At a Particular Time, a Radioactive Source a Has a Decay

question 59

Multiple Choice

At a particular time, a radioactive source A has a decay rate of 1.60 × 10¹¹ Bq and a half-life of 15.0 d, and a second source B has a decay rate of 8.50 × 10¹¹ Bq. Sources A and B have the same decay rate 45.0 d later. The half-life of B is

• A) 0.19 d.
• B) 8.3 d.
• C) 2.8 d.
• D) 5.4 d.
• E) 28 d.

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Definitions:

Deposit

A sum of money placed into an account or given to a party as security for the fulfillment of a contract.

Return

The gain or loss on an investment over a specific period, typically expressed as a percentage of the investment's initial cost.

Annuity

An annuity is a financial product that pays out a fixed stream of payments to an individual, primarily used as an income stream for retirees.

Income

Money received, especially on a regular basis, for work or through investments.