Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET2013PhysicsNuclear PhysicsActual

The half-life of a radioactive isotope X is 20 yr . It decays to another element Y which is stable. The two elements X and Y were found to be in the ratio 1: 7 in a sample of a given rock. The age of the rock is estimated to be

Options

  1. A40 yr
  2. B60 y r
  3. C80 yr
  4. D100 yr

Correct answer

B. 60 y r

Step-by-step solution

( As aligned N N₀ = & ( 1 2 )^n & N N₀ = ( 1 2 )^3= 1 8 aligned Number of half lives =3 aligned & T & =20 yr & T & = t n aligned or t=T n=20 3 yr =60 yr

Practice Nuclear Physics on Quantrex Academy →

More from Nuclear Physics

Consider the following nuclear fission reaction ₀^1 n + ₉₂²³⁵U _Z^A Y + ₄₁⁹⁹Nb + neutrons . If 4 neutrons are released during the fission process, then A and Z are 2026Two spherical nuclei have mass numbers 216 and 64 with their radii R₁ and R₂ respectively. The ratio R₁ R₂ is 2026At time t = 0 , the activity of a radioactive substance is 1600 Bq. At t= 8 s, the activity remains 100 Bq. The activity at t = 2 s, the is 2026A radioactive nucleus ₉₂X²³⁵ decays to ₉₁Y²³¹ . Which of the following particles are emitted? 2026In a given reaction, ^ A _ Z X ^ A _ Z+1 Y ^ A-4 _ Z-1 K ^ A-4 _ Z-1 K the radioactive radiations are emitted in the sequence of 2026When a nucleus in an atom undergoes a radioactive decay, the atomic number and/or mass number of the atom 2026A common example of ^- decay is ₁₅ P ³² ₁₆ S ³² + x + y Then x and y , respectively, stand for 2026For a radioactive nucleus that undergoes ^+ decay, which of the following CANNOT occur? 2026 Full Nuclear Physics list All NEET PYQs