Technimum-99 has a half-life of 6 hours. If there is 300 mg of it. How much will be left in 48 hours?
Correct answer: C. 1.17 mg
- A. 1.58 mg
- B. 1.25 mg
- C. 1.17 mg
- D. 2.56 mg
Explanation
The explanation is given below: Technetium-99m (Tc-99m) has a half-life of 6 hours. You start with 300 mg of it. After 48 hours, you can use this formula to find how much is left: Amount left = Initial amount × (1/2)^(time / half-life) Plug in the values: Amount left = 300 mg × (1/2)^(48 hours / 6 hours) Calculate: Amount left = 300 mg × (1/2)^8 Now, calculate the result: Amount left ≈ 1.1719 mg So, after 48 hours, approximately 1.1719 mg of Technetium-99m will remain from the initial 300 mg.
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About Half-life and Rate of Decay
Half-life is the time required for half the unstable nuclei in a sample to decay, and it remains constant for a particular radioactive nuclide. Questions use the exponential decay law, decay constant, activity, remaining quantity and mean life. Radioactive decay is random for individual nuclei but predictable for large samples.
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