| ⇦ | 
| ⇨ |
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 thermodynamic system undergoes cyclic process ABCDA as shown in figure
- A bar magnet having a magnetic moment of 2 x 10⁴JT⁻¹ is free to rotate in a horizontal
- A spring has time period T. It is cut into n equal parts. The time period of each part
- Calculate the charge on equivalent capacitance of the conbination shown in figure
- In producing chlorine through electrolysis 100 watt power at 1125 V is being
Topics: Atoms and Nuclei
(136)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- A thermodynamic system undergoes cyclic process ABCDA as shown in figure
- A bar magnet having a magnetic moment of 2 x 10⁴JT⁻¹ is free to rotate in a horizontal
- A spring has time period T. It is cut into n equal parts. The time period of each part
- Calculate the charge on equivalent capacitance of the conbination shown in figure
- In producing chlorine through electrolysis 100 watt power at 1125 V is being
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