Home
Class 12
PHYSICS
A radio isotope X with a half-life 1.4 x...

A radio isotope `X` with a half-life `1.4 xx 10^9` years decays of `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.

A

`1.96 xx 10^(9)` years

B

`3.92 xx 10^(9)` years

C

`4.20 xx 10^(9)` years

D

`8.40 xx 10^(9)` years

Text Solution

Verified by Experts

The correct Answer is:
C
Promotional Banner

Topper's Solved these Questions

  • ATOMS, MOLECULES AND NUCLEI

    TARGET PUBLICATION|Exercise Evaluation test|19 Videos

  • ATOMS, MOLECULES AND NUCLEI

    TARGET PUBLICATION|Exercise Critical Thinking|62 Videos

  • CIRCULAR MOTION

    TARGET PUBLICATION|Exercise EVALUATION TEST|11 Videos
TARGET PUBLICATION-ATOMS, MOLECULES AND NUCLEI -Competitive Thinking
  1. The half-life of a radioactive isotope X is 20 yr. It decays to anothe...

    Text Solution

    |

  2. The half-life of a radioactive sample is 6.93 days. After how many day...

    Text Solution

    |

  3. A radio isotope X with a half-life 1.4 xx 10^9 years decays of Y which...

    Text Solution

    |

  4. Radioactive material 'A' has decay constant '8 lamda' and material 'B'...

    Text Solution

    |

  5. The half-life period of a radioactive substance is 5 min. The amount o...

    Text Solution

    |

  6. For a radioactive material, half-life is 10 minutes. If initially ther...

    Text Solution

    |

  7. Two radioactive materials have decay constant 5lambda&lambda. If initi...

    Text Solution

    |

  8. A radioactive material decays by simulataneous emission of two particl...

    Text Solution

    |

  9. A radioactive nucleus can decay by two different processes. The half l...

    Text Solution

    |

  10. If the half-life of a radioactive sample is 10 hours its mean life is

    Text Solution

    |

  11. A radioactive nucleus A with a half life T, decays into nucleus B. At ...

    Text Solution

    |

  12. The half-life of a radioactive element is 100 minutes . The time inte...

    Text Solution

    |

  13. The half-life of a radioactive substance is 30 minutes, The time (in m...

    Text Solution

    |

  14. Half life of a radio-active substance is 20 minutes. The time between ...

    Text Solution

    |

  15. Half-life of a radioactive substance A and B are, respectively, 20 min...

    Text Solution

    |

  16. A sample contains 16 gm of radioactive material, the half-life of whic...

    Text Solution

    |

  17. The half-life of tritium is 12.5 years. What mass of tritium of initia...

    Text Solution

    |

  18. A radioactive sample of half life 10 days contains 1000X nuclei. Numbe...

    Text Solution

    |

  19. A radioactive element has rate of disintegration 10,000 disintegrat...

    Text Solution

    |

  20. A certain radioactive element disintegration with a decay constant of ...

    Text Solution

    |