| ⇦ | 
| ⇨ |
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: - In Bohr model of hydrogen atom, the force on the electron depends on the principal
- If c is the velocity of light in free space, the time taken by light to travel
- A parallel beam of fast moving electrons is incident normally on a narrow slit.
- Two waves are represented by the equations y₁ = a sin (?t + kx + 0.57) m
- Two sources P and Q produce notes of frequency 660 Hz each.
Topics: Atoms and Nuclei
(136)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- In Bohr model of hydrogen atom, the force on the electron depends on the principal
- If c is the velocity of light in free space, the time taken by light to travel
- A parallel beam of fast moving electrons is incident normally on a narrow slit.
- Two waves are represented by the equations y₁ = a sin (?t + kx + 0.57) m
- Two sources P and Q produce notes of frequency 660 Hz each.
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