| ⇦ | 
| ⇨ |
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: - A body revolved around the sun 27 times faster than the earth. What is the ratio
- Two metal rods 1 and 2 of same lengths have same temperature difference
- The approximate depth of an ocean is 2700 m. The compressibility of water is
- A simple pendulum oscillates in a vertical plane. When it passes through the mean
- The displacement of a particle varies according to the relation x=4 (cos π t + sin π t)
Topics: Atoms and Nuclei
(136)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- A body revolved around the sun 27 times faster than the earth. What is the ratio
- Two metal rods 1 and 2 of same lengths have same temperature difference
- The approximate depth of an ocean is 2700 m. The compressibility of water is
- A simple pendulum oscillates in a vertical plane. When it passes through the mean
- The displacement of a particle varies according to the relation x=4 (cos π t + sin π t)
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