SATHEE: Nuclear Chemistry - Result Question 9

Nuclear Chemistry - Result Question 9

####12. One microgram of radioactive sodium $_{1} 1^{24} N a$ with a half-life of 15 hours was injected into a living system for a bio-assay. How long will it take for the radioactive subtance to fall up to $25$ of the initial value?

[1996]

(a) 60 hours

(b) 22.5 hours

(d) 30 hours

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Solution:

(d) $N = N_{0} (\frac{1}{2})^{n}$ ; here, $N = \frac{N_{0}}{4}$

$\frac{N_{0}}{4} = N_{0} (\frac{1}{2})^{n} \Rightarrow (\frac{1}{2})^{n} = (\frac{1}{2})^{2} \Rightarrow n = 2$

Total time $(T) = n \times t_{1 / 2} = 2 \times 15 = 30 h r s$

Nuclear Chemistry - Result Question 9

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Nuclear Chemistry - Result Question 9

Solution:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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