# Problem: Americium-241 is used in smoke detectors. It has a first-order rate constant for the radioactive decay of k = 1.6x10-3 yr-1. By contrast, iodine-125, which is used to test for thyroid functioning, has a rate constant for the radioactive decay of k = 0.011 day-1. A) How much of a 1.00 mgsample of americium remains after 4 days?

###### FREE Expert Solution

Recall that radioactive/nuclear decay of isotopes follows first-order kinetics, and the integrated rate law for first-order reactions is:

where:

[N]t = concentration at time t

k = decay constant

t = time

[N]0 = initial concentration.

85% (410 ratings) ###### Problem Details

Americium-241 is used in smoke detectors. It has a first-order rate constant for the radioactive decay of k = 1.6x10-3 yr-1. By contrast, iodine-125, which is used to test for thyroid functioning, has a rate constant for the radioactive decay of k = 0.011 day-1

A) How much of a 1.00 mg

sample of americium remains after 4 days?

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