| ⇦ | 
| ⇨ |
The half life of radioactive isotope ‘X’ is 50 years. It decays to another element ‘Y’ which is stable. The two elements ‘X’ and ‘Y’ were found to be in the ratio of 1 : 15 in a sample of a given rock. The age of the rock was estimated to be
Options
(a) 150 years
(b) 200 years
(c) 250 years
(d) 100 years
Correct Answer:
200 years
Explanation:
Let no. of atoms in X = Nₛ, No. of atoms in Y = Nₜ
By eq. Nₛ / Nₜ = 1/15
Part of Nₛ = 1/16 (Nₛ + Nₜ) = 1/2⁴ (Nₛ + Nₜ)
So, total 4 half lives are passed, so, age of rock is 4 x 50 = 200 years.
Related Questions: - A carnot’s engine operates with source at 127° C and sink at 27°C
- The rest mass of a body is m1. It moves with a velocity of 0.6c, then its relativistic
- If v is the speed of sound in air, then the shortest length of the closed pipe
- When two displacements represented by y₁=a sin(?t) are superimposed the motion is
- Efficiency of a Carnot engine is 50% when temperature of sink is 500K. In order
Topics: Radioactivity
(83)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- A carnot’s engine operates with source at 127° C and sink at 27°C
- The rest mass of a body is m1. It moves with a velocity of 0.6c, then its relativistic
- If v is the speed of sound in air, then the shortest length of the closed pipe
- When two displacements represented by y₁=a sin(?t) are superimposed the motion is
- Efficiency of a Carnot engine is 50% when temperature of sink is 500K. In order
Topics: Radioactivity (83)
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
Leave a Reply