Home
Class 12
PHYSICS
Define the terms (i) mass defect, (ii) b...

Define the terms (i) mass defect, (ii) binding energy for a nucleus and state the relation between the two.
For a given nuclear reaction, the B.E./nucleon of the product nucleus/nuclei is more than that for the original nucleus/nuclei. Is this nuclear reaction exothermic or endothermic in nature? Justify your choice.

Text Solution

Verified by Experts

(i) Mass defect `(Delta m),` of any nucleus `""_(Z)^(A) X` is the difference in the mass of the nucleus ( = M) and the sum of masses of its constituent nucleons ( = M.).
`therefore Delta m = M.-M`
`= [Zm_(p) + (A - Z) m_(n) ] -M`
where `m_(p) and m_(n)` denote the mass of the proton and the neutron respectively.
(ii) Binding energy is the energy required to separate a nucleus into its constituent nucleons. The relation between the two is
`"B. E." = ("mass defect") xx c^(2)`.
(iii) There is a release of energy i.e., the reaction is exothermic.
Reason : Increase in B.F/nucleon implies that more mass has been converted into energy. This would result in release of energy.
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • NUCLEI

    OSWAAL PUBLICATION|Exercise TOPIC -2 (Long Answer Type Questions)|2 Videos

  • NUCLEI

    OSWAAL PUBLICATION|Exercise TOPIC -2 (Numerical Problems)|3 Videos

  • NUCLEI

    OSWAAL PUBLICATION|Exercise TOPIC -2 (Short Answer Type Questions-I)|2 Videos

  • MOVING CHARGES & MAGNETISM

    OSWAAL PUBLICATION|Exercise TOPIC-3 (Current Carrying Conductor & Galvanometer) (Numerical Problem)|1 Videos

  • RAY OPTICS AND OPTICAL INSTRUMENTS

    OSWAAL PUBLICATION|Exercise TOPIC-3(Numerical Problems)|3 Videos

Similar Questions

Explore conceptually related problems

Define (i) mass defect and (ii) specific binding energy of a nucleus. Show that 1 amu = 931 MeV.

Draw a plot of BE/A versus mass number A for 2 le A le 170 . Use this graph to explain the release of energy in the process of nuclear fusion of two light nuclei. OR Using the curve for the binding energy per nucleon as a function of mass number A, state clearly how the release in energy in the processes of nuclear fission and nuclear fusion can be explained. OR Draw a plot of the binding energy per nucleon as a function of mass number for a large number of nuclei, 2 lt A lt 240 . How do you explain the constancy of binding energy per nucleon in the range 30 lt A lt 170 using the property that nuclear force is short-ranged ?

Knowledge Check

  • The above is a plot of binding energy per nucleon E_(b) , against the nuclear mass M, A,B,C,D,E,F correspond to different nuclei. Consider four reactions: (i) A+B to C+e (ii) C to A+B+epsi (iii) D+E to F+epsi and (iv) F to D+E+epsi where epsi is the energy released? In which reaction is epsi positive?

    A
    (ii) and (iv)
    B
    (ii) and (iii)
    C
    (i) and (iv)
    D
    (i) and (iii)

  • The B.E. per nucleon of ""_(1)H^(2) and ""_(2)He^(4) are 1.1 MeV and 7 MeV respectively. If two deuteron (""_(1)H^(2)) nuclei react to form single helium nucleus, the energy released

    A
    13.9 MeV
    B
    23.6 MeV
    C
    26.9 MeV
    D
    19.2 MeV.

  • In the nuclear fusion reaction ""_(1)^(2)H+""_(1)^(3)H to ""_(2)^(4)He+n given that the repulsive potential energy between two nuclei is -7.7 xx 10^(-14)J, the temp. at which gases must be heated to initiate the reaction is nearly : (k=1.38 xx 10^(-23))

    A
    `10^(7)K`
    B
    `10^(3)K`
    C
    `10^(9)K`
    D
    `10^(7)K`

    • Similar Questions

    Explore conceptually related problems

    Out of the two elements A and B with mass number 2 and 235 respectively, which one is suitable for making : (i) a nuclear reactor (ii) a hydrogen bomb. Name the nuclear reaction involved in each case. Write one difference between the two types of nuclear reactions.

    The Q value of a nuclear reaction A + b to C + d is defined by Q = [m_A + m_b – m_C – m_d]c^2 where the masses refer to the respective nuclei. Determine from the given data the Q-value of the following reactions and state whether the reactions are exothermic or endothermic. (i) ""_(1)^(1)H + ""_(1)^(3)H to _(1)^(2)H + _(1)^(2)H (ii) ""_(6)^(12)C + ""_(6)^(12)C to ""_(10)^(20)Ne + ""_(2)^(4)He Atomic masses are given to be m (""_(1)^(2)H) = 2.014102 u m (""_(1)^(3)H) = 3.016049 u m (""_(6)^(12)C ) = 12.000000 u m (""_(10)^(20)Ne ) = 19.992439 u .

    Given below are some famous numbers associated with electromagnetic radiations in different contexts in physics. State the part of the electromagnetic spectrum to which each belongs. (a) 21 cm (wavelength emitted by atomic hydrogen in interstellar space). (b) 1057 MHz (frequency of radiation arising from two close energy levels in hydrogen, known as Lamb shift). (c) 2.7 K [temperature associated with the isotropic radiation filling all space-thought to be a relic of the ‘big-bang’ origin of the universe]. (d) 5890 Å - 5896 Å [double lines of sodium] (e) 14.4 keV [energy of a particular transition in ""^(57)Fe nucleus associated with a famous high resolution spectroscopic method (Mössbauer spectroscopy)].

    A thermal neutron strikes U_(92)^(235) nucleus to produce fission. The nuclear reaction is as given below : n_(0)^(1) + U_(92)^(235) to Ba_(56)^(141) + Kr_(36)^(92) +3n_(0)^(1) + E Calculate the energy released in MeV. Hence calculate the total energy released in the fission of 1 Kg of U_(92)^(235) . Given mass of U_(92)^(235) = 235.043933 amu Mass of neutron n_(0)^(1) =1.008665 amu Mass of Ba_(56)^(141)=140.917700 amu Mass of Kr_(36)^(92)=91.895400 amu

    Home
    Profile