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A 1.5 kg sample of californium-253 (Cf-253) undergoes radioactive decay. After 89 days, 46.875 grams remain. What is the half-life of this isotope? Show your work to earn full credit. Your answer.

A) 25 days
B) 50 days
C) 75 days
D) 100 days

User ErTR
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1 Answer

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Final answer:

The half-life of Californium-253 (Cf-253) is approximately 5.29 days.

Step-by-step explanation:

The half-life of an isotope is the time it takes for half of a sample to decay. In this case, we can use the information given to calculate the half-life of Californium-253 (Cf-253). We know that after 89 days, 46.875 grams of Cf-253 remain. We can set up an equation using the half-life formula:

Remaining mass = Initial mass * (1/2)^(t/half-life)

Substituting the given values:

46.875 g = 1.5 kg * (1/2)^(89/half-life)

We can solve this equation to find the value of the half-life:

46.875 g / 1500 g = (1/2)^(89/half-life)

0.03125 = (1/2)^(89/half-life)

To simplify, we can take the logarithm of both sides:

log(0.03125) = (89/half-life) * log(1/2)

Using logarithm properties:

log(0.03125) = -5 = (89/half-life) * -0.301

Solving for half-life:

half-life = 89 * (-0.301) / -5

half-life ≈ 5.29

Therefore, the half-life of Californium-253 is approximately 5.29 days.

User Stephen Lombardo
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