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प्रश्न
In a typical nuclear reaction, e.g.
`"_1^2H+"_1^2H ->"_2^3He + n + 3.27 \text { MeV },`
although number of nucleons is conserved, yet energy is released. How? Explain.
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उत्तर
In a nuclear reaction, the sum of the masses of the target nucleus `("_1^2H)`and the bombarding particle `("_1^2H)` may be greater or less than the sum of the masses of the product nucleus `("_1^3He)` and the outgoing particle `("_0^1n).` So from the law of conservation of mass-energy some energy (3.27 MeV) is evolved or involved in a nuclear reaction. This energy is called Q-value of the nuclear reaction.
संबंधित प्रश्न
Write the relationship between the size of a nucleus and its mass number (A)?
Suppose we have 12 protons and 12 neutrons. We can assemble them to form either a 24Mg nucleus or two 12C nuclei. In which of the two cases more energy will be liberated?
The mass number of a nucleus is equal to
As the mass number A increases, the binding energy per nucleon in a nucleus
For nuclei with A > 100,
(a) the binding energy of the nucleus decreases on an average as A increases
(b) the binding energy per nucleon decreases on an average as A increases
(c) if the nucleus breaks into two roughly equal parts, energy is released
(d) if two nuclei fuse to form a bigger nucleus, energy is released.
Assume that the mass of a nucleus is approximately given by M = Amp where A is the mass number. Estimate the density of matter in kgm−3 inside a nucleus. What is the specific gravity of nuclear matter?
Calculate the mass of an α-particle. Its Its binding energy is 28.2 MeV.
(Use Mass of proton mp = 1.007276 u, Mass of `""_1^1"H"` atom = 1.007825 u, Mass of neutron mn = 1.008665 u, Mass of electron = 0.0005486 u ≈ 511 keV/c2,1 u = 931 MeV/c2.)
(a) Calculate the energy released if 238U emits an α-particle. (b) Calculate the energy to be supplied to 238U it two protons and two neutrons are to be emitted one by one. The atomic masses of 238U, 234Th and 4He are 238.0508 u, 234.04363 u and 4.00260 u respectively.
(Use Mass of proton mp = 1.007276 u, Mass of `""_1^1"H"` atom = 1.007825 u, Mass of neutron mn = 1.008665 u, Mass of electron = 0.0005486 u ≈ 511 keV/c2,1 u = 931 MeV/c2.)
What is the unit of mass when measured on the atomic scale?
The force 'F' acting on a particle of mass 'm' is indicated by the force-time graph shown below. The change in momentum of the particle over the time interval from zero to 8s is:

