| ⇦ | 
| ⇨ |
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 particle of mass m is projected with velocity v making an angle of 45° with
- If L and C denote inductance and capacitance,then the dimensions of L-C are
- If force is proportional to square of velocity, then the dimension of proportionality
- A cycle wheel of radius 4 m completes one revolution in two seconds. Then acceleration
- To convert a 800 mV range millivoltmeter of resistance 40Ω into an ammeter of 100 mA
Topics: Atoms and Nuclei
(136)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- A particle of mass m is projected with velocity v making an angle of 45° with
- If L and C denote inductance and capacitance,then the dimensions of L-C are
- If force is proportional to square of velocity, then the dimension of proportionality
- A cycle wheel of radius 4 m completes one revolution in two seconds. Then acceleration
- To convert a 800 mV range millivoltmeter of resistance 40Ω into an ammeter of 100 mA
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