I am doing practice problems right now and I need someone to determine in my answer are wrong or not. Half-lives are very confusing.
A patient is injected with 15 mCi of technetium-99 (t1/2 = 6.02 hours) and examined with a gamma camera to assess her kidney function. How much technetium-99 remains in her body after 4 hours? 8 hours?
If you get a different answer, please post how you did it.
For 4 hours I got: 9.967 mCi
For 8 hours I got: 4.934 mCi
A patient is injected with 15 mCi of technetium-99 (t1/2 = 6.02 hours) and examined with a gamma camera to assess her kidney function. How much technetium-99 remains in her body after 4 hours? 8 hours?
If you get a different answer, please post how you did it.
For 4 hours I got: 9.967 mCi
For 8 hours I got: 4.934 mCi
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first, find k for the reaction
1/2life = 0.693 / K
0.693 / 6.02hr = K = 0.115
[A] = [Aº] x e^(-kt).....so
[A] = 15mCi x e^(-0.115 x 4hr)
[A] = 9.47mCi after 4 hr
[A] = 15 mCi x e^(-0.115 x 8hr)
[A] = 5.98 mCi
1/2life = 0.693 / K
0.693 / 6.02hr = K = 0.115
[A] = [Aº] x e^(-kt).....so
[A] = 15mCi x e^(-0.115 x 4hr)
[A] = 9.47mCi after 4 hr
[A] = 15 mCi x e^(-0.115 x 8hr)
[A] = 5.98 mCi