Advertisements
Advertisements
प्रश्न
A free neutron decays to a proton but a free proton does not decay to a neutron. This is because
विकल्प
neutron is a composite particle made of a proton and an electron whereas proton is a fundamental particle
neutron is an uncharged particle whereas proton is a charged particle
neutron has large rest mass than the proton
weak forces can operate in a neutron but not in a proton
Advertisements
उत्तर
neutron has large rest mass than the proton.
A nucleus is made up of two fundamental particles- neutrons and protons. If a nucleus has more number of neutrons than what is needed to have stability, then neutrons decay into protons and if there's an excess of protons, then they decay to form neutrons. Since a neutron has larger rest mass than a proton, the Q-value of its decay reaction is positive and a free neutron decays to a proton, while an isolated proton cannot decay to a neutron as the Q-value of its decay reaction is negative. Hence, it is physically not possible.
APPEARS IN
संबंधित प्रश्न
Suppose, we think of fission of a `""_26^56"Fe"` nucleus into two equal fragments `""_13^28"Al"`. Is the fission energetically possible? Argue by working out Q of the process. Given `"m"(""_26^56 "Fe") = 55.93494 "u"` and `"m"(""_13^28 "Al") = 27.98191 "u"`.
The fission properties of `""_94^239"Pu"` are very similar to those of `""_92^235 "U"`. The average energy released per fission is 180 MeV. How much energy, in MeV, is released if all the atoms in 1 kg of pure `""_94^239 "Pu"` undergo fission?
A 1000 MW fission reactor consumes half of its fuel in 5.00 y. How much `""_92^235"U"` did it contain initially? Assume that the reactor operates 80% of the time, that all the energy generated arises from the fission of `""92^235"U"` and that this nuclide is consumed only by the fission process.
The mass of a neutral carbon atom in ground state is
As compared to 12C atom, 14C atom has
The heavier nuclei tend to have larger N/Z ratio because
(a) a neutron is heavier than a proton
(b) a neutron is an unstable particle
(c) a neutron does not exert electric repulsion
(d) Coulomb forces have longer range compared to the nuclear forces.
Calculate the energy released by 1g of natural uranium assuming 200 MeV is released in each fission event and that the fissionable isotope 235U has an abundance of 0.7% by weight in natural uranium.
A uranium reactor develops thermal energy at a rate of 300 MW. Calculate the amount of 235U being consumed every second. Average released per fission is 200 MeV.
In a nuclear reactor, moderators slow down the neutrons which come out in a fission process. The moderator used have light nuclei. Heavy nuclei will not serve the purpose because ____.
If in nuclear fusion process the masses of the fusing nuclei be m1 and m2 and the mass of the resultant nucleus be m3, then:
Power generated by a nuclear reactor is given by P = n E / t. Here n represents:
\[\ce{^290_80X ->[\alpha] Y ->[e+] Z ->[\beta-] P ->[e-] Q}\]
In the nuclear emission stated above, the mass number and atomic number of the product Q respectively, are:
Nuclear fission is best defined as:
In the fission of uranium-235, the particle that bombards the nucleus to initiate the reaction is a:
When \(_{92}^{235}U\) captures a bombarding neutron, the intermediate nucleus formed before it splits is:
Complete the fission reaction: \[_{0}^{1}n + _{92}^{235}U \to _{92}^{236}U \to _{56}^{144}Ba + _{36}^{89}Kr + \,?\]
In the neutron-induced fission of uranium-235 that produces \(_{51}^{133}Sb\) and \(_{41}^{99}Nb\) as fragments, the number of neutrons released is:
The disintegration energy released in a fission event first appears as:
