Recent questions and answers in Nuclei

Complete the reaction : $n+_{92}U^{235} \to _{56} Ba^{144}$ + _____ $+ 3n$

answered Aug 16, 2016 by meena.p

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The binding energy of deuteron is $2.2 \;Mev$ and that of $_2He^4$ in $28\;Mev$ . If two deuterons are fused to form one $_2He^4$ , then the energy released is

answered Aug 16, 2016 by meena.p

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A radioactive substance decays to $\large\frac{1}{16}$ of its initial activity in 40 days . The half life of the radio active substance expressed in days is

answered Aug 16, 2016 by meena.p

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The radius of $G_e$ nuclide is measured to be twice the radius of $_4 Be^9$ . The no nucleolus in $Ge$ are

answered Aug 16, 2016 by meena.p

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Half lives of two ratio active substance A and B are respectively 20 minutes . Initially the samples of A and B have equal number of nuclei. after 80 minutes the ratio of remaining numbers of A and B nuclei is

answered Aug 16, 2016 by meena.p

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Two H atoms in the ground state collide inelastically . The maximum amount by which their combined kinetic energy is reduced is

answered Aug 10, 2016 by meena.p

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Taking the Bohr radius as $a_0 = 53\;pm$ the radius of $Li^{++}$ ion in its ground state on the basis of Bohr's model will be about

answered Aug 10, 2016 by meena.p

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Obtains the maximum kinetic enery of $\beta$ particles and the radiation frequencies of $\gamma$ decays in the delay scheme . You are given that $m(_{79}Au^{198})=197.9682334\;u$ $\qquad m(_{80}Hg^{198})=197.966760\;u$

answered Aug 10, 2016 by meena.p

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Consider the so called $D-T reaction$ (determination - tritium) calculate the energy released in Mev in this reaction from the data $m(_1H^2)=2.0141024$ and $m(_1H^3) =3.0160494$

answered Aug 9, 2016 by meena.p

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Consider the so called D -T reaction (deuterium - tritium fusion ) $_1H^2 +_1H^{3} \to _2He^{4} +n$ consider the radius of both detriment and tritium to be approximately $2.0\;fm$ . What is the kinetic energy needed to overcome the coulomb repulsion between the two nuclei? To what temperature must the gases be heated to initiate the reaction ?

answered Aug 9, 2016 by meena.p

1 answer

Consider the fission of $_{92}U^{238}$ by fast neutrons. In one fission event , no neutron are emitted and the final stable end products , after the beta decay of the primary fragments are $_{58}Ce ^{140}$ and $_{44}Ru ^{99}$ . Calculate Q for this fission process . The relevant atomic and particle masses are : $m(_92U^{238})=238.05079\;u$ $m(_{34} Ru^{99}) = 98.90594\;u$ $m(_{58}Ce^{140})=139.90543\;u$

answered Aug 9, 2016 by meena.p

1 answer

Under certain circumstance , a nucleolus can decay by emitting a particle more massive than an $\alpha$ particle . Consider the following : $_{88}Ra^{223} \to _{86} Rn ^{219} +_2 He ^{14}$ Calculate the Q value for this decay and determine if it energetically possible .

answered Aug 9, 2016 by meena.p

1 answer

Under certain circumstance , a nucleolus can decay by emitting a particle more massive than an $\alpha$ particle . Consider the following : $_{88}Ra^{223} \to _{82} Pb ^{209} +_6C^{14}$ Calculate the Q value for this decay and determine if it energetically possible .

answered Aug 9, 2016 by meena.p

2 answers

A Source contains two phosphors radio nuclides $_{15}P^{32}(T_{1/2}=14.3\;days)$ and $_{15}P^{33} (T_{1/2} =25.3\;day)$ Initially $10\%$ of the decays come from $_{15}P^{33}$ . How long one must wait until $90\%$ do so ?

answered Aug 5, 2016 by meena.p

1 answer

The neutron separation energy is defined to be the energy required to remove a neutron from a nucleus. Obtain the neutron separation energy of the nuclei $_{20}Ca ^{41}$ from the following data : $_{13} Al ^{27} \to _{13}Al^{26}+_0 n^1$

answered Aug 5, 2016 by meena.p

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The neutron separation energy is defined to be the energy required to remove a neutron from a nucleus. Obtain the neutron separation energy of the nuclei $_{20}Ca ^{41}$ from the following data : $m(_{20}Ca^{40})=39.962591\;u,m(_{20}Ca^{41})=40.962278\;u,m(_{13}Al^{27})=26.981514\;u$

answered Aug 5, 2016 by meena.p

1 answer

In a periodic table the average atomic mass of magnesium is given as $24.312\;u$ The average value is based on their relative natural abundance on earth. The three isotopes and their masses are $_{12} Mg^{24}(23.98504\;u)$ , $_{12} Mg^{25}(24.98584\;u)$ and $_{12} Mg^{24}$ is $78.99\%$ by mass. Calculate the abundances of the other two isotopes.

answered Aug 4, 2016 by meena.p

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For the $\beta^+$ (positron) emission from a nucleus, there is another competing process known known as electron capture.Electron from an inner orbit is captured by the nucleus and a neutrino is emitted. $\beta^+$ emission is energetically allowed , electron capure is necessarily allowed but not vice- versa . Is this a true statement ?

answered Aug 4, 2016 by meena.p

1 answer

From the relation $R=R_0A^{1/3}$ , where $R_0$ is a constant and A is the mass number of a nucleus , show that the nuclear matter density is nearly a constant (ie independent of A)

answered Aug 4, 2016 by meena.p

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Calculate the height of potential barrier for a head on collision of two denterons. The effective radius of deuteron can be taken to be $2 fm$ . Note that height of potential barrier is given by the coulmb repulsion between two denterons when they just touch each other .

answered Aug 3, 2016 by meena.p

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How long an electric lamp of $100 w$ be kept glowing by fusion of $2.0\;kg$ of deuterium ?

answered Aug 3, 2016 by meena.p

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A thousand reactor factor consume half of its fuel in 5.00 y . How much $_{92} U^{235}$ did it contain initially ? Assume that the reactor operates $80\%$ of the time and that all the energy generated arises from the fission of $_{92}U^{235}$ and that this nuclide is consumed by the fission process ?

answered Aug 3, 2016 by meena.p

1 answer

The fission properties of $_{84}Pu^{237}$ are similar to those of $_{92} U^{35}$ . 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 $_{94} Pu ^{239}$ undergo fission .

answered Aug 3, 2016 by meena.p

1 answer

Suppose we think of fission of a $_{26}Fe^{56}$ nucleus into two fragment $_{13} Al ^{26}$ . Is the fission energetically possible ? Argue by working out Q of the process. cives.

answered Aug 3, 2016 by meena.p

1 answer

The Q value of a nuclear reaction $A+b=c+A$ is defined by $[m_A+m_b-m_c-m_d] C^2$ where masses refers to the respective nuclei. Determine from the given data the Q value of the following reaction and state whether the reaction are exothermic or endothermic . $_6C^{12}+_6C^{12} \to _{10}Ne^{20} +_2He^4$

answered Aug 2, 2016 by meena.p

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The Q value of a nuclear reaction $A+b=c+A$ is defined by $[m_A+m_b-m_c-m_d] C^2$ where masses refers to the respective nuclei. Determine from the given data the Q value of the following reaction and state whether the reaction are exothermic or endothermic . $_1H^1+_1H^3 \to _1H^2 +_1H^2$

answered Aug 2, 2016 by meena.p

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The nucleus $_{10} Ne ^{23}$ decays by $\beta ^{-}$ emission. write down the $\beta^{-}$ decay equation and determine the maximum kinetic energy of the electrons emitted from the following data. $m (_{10} Ne ^{23} ) = 22.994466\;amu \;\qquad m (_{11} Na ^{23} ) = 22.989770\;amu$

answered Jul 22, 2016 by meena.p

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The radio nuclide $_6C^{11}$ decays according to $_6C^{11} \to _5B^{11}+e^++\gamma$ half life $=20.3\;min$ The maximum energy of the emitted position is $0.960\;Mev$ given the mass values $m(_6C^{11})=11.011434 \;u\;m (_6B^{11})=11.009305$ calculate Q and compare it with maximum energy of position emitted .

answered Jul 13, 2016 by meena.p

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Given $m(_{86} R_n ^{220} =220.1137\;u; m(_{84}Po^{216})=216.00189u$ and $m_{\alpha}=4.00260 \;u$ Find the Q value and K.E of the emitted $\alpha$ particle in the $\alpha$ decay of $_{86} Rn ^{220}$

answered Jul 13, 2016 by meena.p

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Find the Q value and the kinetic energy of emitted $\alpha$ particle in the $\alpha$ decay of $_{88} Ra ^{226}$

answered Jul 13, 2016 by meena.p

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Obtain Approximately the ratio of the nuclear radii of the gold isotope $_{79} Au^{197}$ and silver isotope $_{4}Ag^{107}$

answered Jul 13, 2016 by meena.p

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The half life of $_{38} Sr ^{90}$ is 28 years . What is the disintegration rate of $15\;mg$ of this isotope?

answered Jul 13, 2016 by meena.p

1 answer