A radioactive isotope X with a half-life of 
years decays to Y which is stable. A sample of rock from the moon was found to contain both the elements X and Y which were in the ratio of 
. The age of the rock is
A
years
B
years C
years
D
years
Text Solution
Verified by ExpertsThe correct answer is:
C
If in the rock there is no 
element, then the time taken by element 
to reduce to 
th the initial value will be equal to 
or 
Therefore, from the beginning three half life time is spent. Hence the age of the rock is 
years.
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems
An -particle of 5 MeV energy strikes with a nucleus of uranium at stationary at an scattering angl…
The ratio of the speed of the electrons in the ground state of hydrogen to the speed of light in va…
In hydrogen atom, electron makes transition from to level. Recoil momentum of the atom will be
A sodium atom is in one of the states labeled 'Lowest excited levels'. It remains in that state for…
An energy of 24.6 eV is required to remove one of the electrons from a neutral helium atom. The ene…
A hydrogen atom in its ground state absorbs 10.2 eV of energy. The orbital angular momentum is incr…