What is the decay factor for 99mTc over a period of 1.5 hours?

What is the decay factor for 99mTc over a period of 1.5 hours?

• A. 0.84
• B. 0.68
• C. 0.75
• D. 0.50

Answer: (A)

To determine the decay factor for technetium-99m (99mTc) over a period of 1.5 hours, it is essential to understand the half-life of the isotope and how to compute the decay factor using that information. The half-life of 99mTc is approximately 6 hours. To find the decay factor after 1.5 hours, you first need to understand how many half-lives fit into that time frame. Since 1.5 hours is a quarter of the 6-hour half-life, you can calculate the decay as follows: 1. The fraction of the half-life that has elapsed is \( \frac{1.5 \, \text{hours}}{6 \, \text{hours}} = 0.25 \). 2. The decay factor can be calculated using the formula: \[ \text{Decay Factor} = \left(\frac{1}{2}\right)^{\text{number of half-lives}} = \left(\frac{1}{2}\right)^{0.25} \] This yields a decay factor of approximately 0.84. Overall, this means that after 1.5 hours, about 84

To determine the decay factor for technetium-99m (99mTc) over a period of 1.5 hours, it is essential to understand the half-life of the isotope and how to compute the decay factor using that information. The half-life of 99mTc is approximately 6 hours.

To find the decay factor after 1.5 hours, you first need to understand how many half-lives fit into that time frame. Since 1.5 hours is a quarter of the 6-hour half-life, you can calculate the decay as follows:

1. The fraction of the half-life that has elapsed is ( \frac{1.5 , \text{hours}}{6 , \text{hours}} = 0.25 ).

2. The decay factor can be calculated using the formula:

[ \text{Decay Factor} = \left(\frac{1}{2}\right)^{\text{number of half-lives}} = \left(\frac{1}{2}\right)^{0.25} ]

This yields a decay factor of approximately 0.84.

Overall, this means that after 1.5 hours, about 84