| ⇦ | 
| ⇨ |
A radio isotope X with a half life 1.4 x 10⁹ years decays to Y which is stable. A sample of the rock from a cave was found to contain X and Y in the ratio 1:7. The age of the rock is
Options
(a) 1.96 x 10⁹ years
(b) 3.92 x 10⁹ years
(c) 4.20 x 10⁹ years
(d) 8.40 x 10⁹ years
Correct Answer:
4.20 x 10⁹ years
Explanation:
No explanation available. Be the first to write the explanation for this question by commenting below.
Related Questions: - An inclined plane makes an angle of 30° with the horizontal.A solid sphere
- The area of cross-section of one limb of an U-tube is twice that of the other.
- Stress to strain ratio is equivalent to
- The upper half of an inclined plane of inclination θ is perfectly smooth while lower
- If n₁, n₂ and n₃ are the fundamental frequencies of three segments into which a string
Topics: Atoms and Nuclei
(136)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- An inclined plane makes an angle of 30° with the horizontal.A solid sphere
- The area of cross-section of one limb of an U-tube is twice that of the other.
- Stress to strain ratio is equivalent to
- The upper half of an inclined plane of inclination θ is perfectly smooth while lower
- If n₁, n₂ and n₃ are the fundamental frequencies of three segments into which a string
Topics: Atoms and Nuclei (136)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
18000+ students are using NEETLab to improve their score. What about you?
Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.
Share this page with your friends
X/Y=1/7
Y=7X
Let the initial atoms be N.
Then,
X+Y=N
X+7X=N
8X=N
X=N/8
Hence, the final atoms be N/8.
N/8/N=(1/2)^n
(1/8)^3=(1/2)^n
n=3
Then, t=n×T1/2
t=3×1.4×10^9
t=4.2×10^9