Home
Class 12
PHYSICS
The half life of I""^(131) is 8 day. Giv...

The half life of `I""^(131)` is `8 day`. Given a sample of `I""^(131)` at t=0, we can assert that
a)No nucleus will decay at `t=4day`
b)No nucleus will decay before ` t=8day`
c)All nucleus will decay before `t=16day`
d)A given nucleus may decay before at any time after `t=0`

Text Solution

Verified by Experts

The correct Answer is:
D
Number of nuclei decreases experientially
`N=N_(0)e^(-lambdat)` and Rate of decay `(-(dN)/(dt))=lambdaN`
Therefore, decay process lasts upto `t=oo`. Therefore a given nucleus may decay at any time after `t=0`.
Promotional Banner

Topper's Solved these Questions

  • SIMPLE HARMONIC MOTION

    ALLEN |Exercise MCQ s|8 Videos

  • SIMPLE HARMONIC MOTION

    ALLEN |Exercise Match The Column|9 Videos

  • SIMPLE HARMONIC MOTION

    ALLEN |Exercise Exercise - 04[A]|25 Videos

  • RACE

    ALLEN |Exercise Basic Maths (Wave Motion & Dopplers Effect) (Stationary waves & doppler effect, beats)|25 Videos

  • TEST PAPER

    ALLEN |Exercise PHYSICS|4 Videos

Similar Questions

Explore conceptually related problems

The half life of radioactive Radon is 3.8 days . The time at the end of which (1)/(20) th of the radon sample will remain undecayed is (given log e = 0.4343 )

To determine the half life of a radioactive element , a student plote a graph of in |(dN(t))/(dt)| versus t , Here |(dN(t))/(dt)| is the rate of radioatuion decay at time t , if the number of radoactive nuclei of this element decreases by a factor of p after 4.16 year the value of p is

A radioactive nucleus X decay to a nucleus Y with a decay with a decay Concept lambda _(x) = 0.1s^(-1) , gamma further decay to a stable nucleus Z with a decay constant lambda_(y) = 1//30 s^(-1) initialy, there are only X nuclei and their number is N_(0) = 10^(20) . Set up the rate equations for the population of X , Y and Z The population of Y nucleus as a function of time is given by N_(y) (1) = N_(0) lambda_(x)l(lambda_(x) - lambda_(y))( (exp(- lambda_(y)t)) Find the time at which N_(y) is maximum and determine the populations X and Z at that instant.

The graph represents the decay of a newly-prepared sample of radioactive nuclide X to a stable nuclide Y. The half-life of X is t. The growth curve for Y intersects the decay curve for X after time T. What is the time T ?

The mass of a nucleus ._(Z)^(A)X is less that the sum of the masses of (A-Z) number of neutrons and Z number of protons in the nucleus.The energy equivalent to the corresponding mass difference is known as the binding energy of the nucleus. A heavy nucleus of mass M can break into two light nuclei of masses m_(1) and m_(2) only if (m_(1)+m_(2)) lt M . Also two light nuclei of masses m_(3) and m_(4) can undergo complete fusion and form a heavy nucleus of mass M'. only if (m_(3)+m_(4)) gt M' . The masses of some neutral atoms are given in the table below: |{:(._(1)^(1)H ,1.007825u , ._(1)^(2)H,2.014102u,._(1)^(3)H,3.016050u,._(2)^(4)He,4.002603u),(._(3)^(6)Li,6.015123u,._(3)^(7)Li,7.016004u,._(30)^(70)Zn,69.925325u, ._(34)^(82)Se,81.916709u),(._(64)^(152)Gd,151.91980u,._(82)^(206)Pb,205.974455u,._(83)^(209)Bi,208.980388u,._(84)^(210)Po,209.982876u):}| Taking kinetic energy ( in KeV ) of the alpha particle, when the nucleus ._(84)^(210)P_(0) at rest undergoes alpha decay, is:

Scientists are working hard to develop nuclear fusion reactor Nuclei of heavy hydrogen, _(1)^(2)H , known as deuteron and denoted by D , can be thought of as a candidate for fusion rector . The D-D reaction is _(1)^(2) H + _(1)^(2) H rarr _(2)^(1) He + n+ energy. In the core of fusion reactor, a gas of heavy hydrogen of _(1)^(2) H is fully ionized into deuteron nuclei and electrons. This collection of _1^2H nuclei and electrons is known as plasma . The nuclei move randomly in the reactor core and occasionally come close enough for nuclear fusion to take place. Usually , the temperature in the reactor core are too high and no material will can be used to confine the to plasma for a time t_(0) before the particles fly away from the core. If n is the density (number volume ) of deuterons , the product nt_(0) is called Lawson number. In one of the criteria , a reactor is termed successful if Lawson number is greater then 5 xx 10^(14) s//cm^(2) it may be helpfull to use the following boltzmann constant lambda = 8.6 xx 10^(-5)eV//k, (e^(2))/(4 pi s_(0)) = 1.44 xx 10^(-9) eVm In the core of nucleus fusion reactor , the gas become plasma because of

A container having base area A_(0) . Contains mercury upto a height l_(0) . At its bottom a thin tube of length 4l_(0) and cross-section area A(AltltA_(0) ) having lower end closed is attached . Initially the length of mercury in tube is 3l_(0) . in reamining part 2 mole of a gas at temperature T is closed as shown in figure . Determine the work done (in joule) by gas if all mercury is displaced from tube by heating slowly the gas in the rear end of the tube by means of a heater. (Given : density of mercury = rho , atmospheric pressure P_(0) = 2l_(0)rhog, C_(v) of gas = 3//2 R, A = (3//rho)m^(2), l_(0) = (1//9) m , all units is S.I. )

ALLEN -SIMPLE HARMONIC MOTION-Exercise-05(B)
  1. X- rays are produced in an X- rays tube operating at a given accelerat...

    Text Solution

    |

  2. The work function of a substance is 4.0 eV. The longest wavelength of ...

    Text Solution

    |

  3. The half life of I""^(131) is 8 day. Given a sample of I""^(131) at t=...

    Text Solution

    |

  4. In hydrogen spectrum the wavelength of H(alpha) line is 656nm, where ...

    Text Solution

    |

  5. .^22 Ne nucleus after absorbing energy decays into two alpha-particles...

    Text Solution

    |

  6. A particle of mass M at rest decays into two particles of masses m(1...

    Text Solution

    |

  7. Which of the following is a correct statement ?

    Text Solution

    |

  8. The half-life period of a radioactive element X is same s the mean lif...

    Text Solution

    |

  9. Order of magnitude of density of uranium nucleus is , [m = 1.67 xx 10^...

    Text Solution

    |

  10. Binding energy per nucleons vs mass curve for nucleus is shown in the ...

    Text Solution

    |

  11. Imagine an atom made of a proton and a hypothetical particle of double...

    Text Solution

    |

  12. In an atom when electrons transition from excited state to ground stat...

    Text Solution

    |

  13. Electrons with energy 80 keV are incident on the tungsten target of an...

    Text Solution

    |

  14. Two radioactive materials X(1) and X(2) have decay constant 11 lambda ...

    Text Solution

    |

  15. The transistion from the state n = 4 to n = 3 in a hydrogen like atom ...

    Text Solution

    |

  16. Graph shows relation between intensity (I),wavelength for X-rays emitt...

    Text Solution

    |

  17. The electron emitted in beta radiation originates from

    Text Solution

    |

  18. A radioactive sample consists of two distinct species having equal num...

    Text Solution

    |

  19. A Hydrogen atom and Li^(++) ion are both in the second excited state....

    Text Solution

    |

  20. The potential difference applied to an X-ray tube is 5 kV and the curr...

    Text Solution

    |