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## Atoms and Nuclei

### Physics

#### Previous Years Questions

More
A nucleus of mass number 189 splits into two nuclei having mass number 125 and 64. The ratio of radius of two daughter n...
NEET 2022
Let T1 and T2 be the energy of an electron in the first and second excited states of hydrogen atoms, respectively. Accor...
NEET 2022
In the given nuclear reaction, the element X is $${}_{11}^{22}Na \to X + {e^ + } + v$$
NEET 2022
The graph which shows the variation of the de Broglie wavelength ($$\lambda$$) of a particle and its associated momentum...
NEET 2022
The half life of a radioactive nuclide is 100 hours. The fraction of original activity that will remain after 150 hours ...
NEET 2021
A nucleus with mass number 240 breaks into two fragments each of mass number 120, the binding per nucleon of unfragmente...
NEET 2021
The energy equivalent of 0.5 g of a substance is :
NEET 2020 Phase 1
For which one of the following, Bohr model is not valid?
NEET 2020 Phase 1
When a uranium isotope $$_{92}^{235}U$$ is bombarded with a neutron, it generates $$_{36}^{89}Kr$$ three neutrons and :...
NEET 2020 Phase 1
The total energy of an electron in an atom in an orbit is –3.4 eV. Its kinetic and potential energies are, respectively.
NEET 2019
$$\alpha$$-particale consists of :
NEET 2019
The ratio of kinetic energy to the total energy of an electron in a Bohr orbit of the hydrogen atom, is
NEET 2018
For a radioactive material, half-life is 10 minutes. If initially there are 600 number of nuclei, the time taken (in min...
NEET 2018
Radioactive material 'A' has decay constant '8 $$\lambda$$' and material 'B' has decay constant '$$\lambda$$'. Initial...
NEET 2017
The ratio of wavelengths of the last line of Balmer series and the last line of Lyman series is
NEET 2017
Given the value of Rydberg constant is 107 m$$-$$1, the wave number of the last line of the Balmer series in hydrogen sp...
NEET 2016 Phase 1
When an $$\alpha$$-particle of mass m moving with velocity v bombards on a heavy nucleus of charge Ze, its distance of ...
NEET 2016 Phase 1
The half-life of a radioactive substance is 30 minutes. The time (in minutes) taken between 40% decay and 85% decay of t...
NEET 2016 Phase 2
If an electron in a hydrogen atom jumps from the 3rd orbit to the 2nd orbit, it emits a photon of wavelength $$\lambda ... NEET 2016 Phase 2 Consider 3rd orbit of He+ (Helium), using non-relativistic approach, the speed of electron in this orbit will be [given ... AIPMT 2015 Cancelled Paper If radius of the$${}_{13}^{27}$$Al nucleus is taken to be RAl, then the radius of$${}_{53}^{125}$$Te nucleus is nearl... AIPMT 2015 Cancelled Paper In the spectrum of hydrogen, the ratio of the longest wavelength in the Lyman series to the longest wavelength in the Ba... AIPMT 2015 A nucleus of uranium decays at rest into nuclei of thorium and helium. Then AIPMT 2015 The binding energy per nucleon of and nuclei are 5.60 MeV and 7.06 MeV respectively. In the nuclear reaction$${}_3^7Li ...
AIPMT 2014
Hydrogen atom in ground state is excited by a monochromatic radiation of $$\lambda$$ = 975 $$\mathop A\limits^ \circ ... AIPMT 2014 A radioactive X with a half life 1.4$$ \times $$109 years decays to Y which is stable. A sample of the rock from a cav... AIPMT 2014$$\alpha $$-particles,$$\beta $$-particles and$$\gamma $$-rays are all having same energy. Their penetrating power in... NEET 2013 (Karnataka) An electron in hydrogen atom makes a transition n1$$ \to $$n2 where n1 and n2 are principal quantum numbers of the two... NEET 2013 (Karnataka) A certain mass of Hydrogen is changed to Helium by the process of fusion. The mass defect in fusion reaction is 0.02866 ... NEET 2013 The half life of a radioactive isotope 'X' is 20 years. It decays to another element 'Y' which is stable. The two elemen... NEET 2013 How does the Binding Energy per nucleon vary with the increase in the number of nucleons ? NEET 2013 (Karnataka) Ratio of longest wave lengths corresponding to Lyman and Balmer series in hydrogen spectrum is NEET 2013 The half life of a radioactive nucleus is 50 days. The time invertal (t2$$-$$t1) between the time t2 when$${2 \over 3...
AIPMT 2012 Mains
An electron of a stationary hydrogen atom passes from the fifth energy level to the ground level. The velocity that the ...
AIPMT 2012 Prelims
Electron in hydrogen atom first jumps from third excited state to second excited state and then from second excited to t...
AIPMT 2012 Prelims
If the nuclear radius of 27Al is 3.6 fermi, the approximate nuclear radius of 64Cu in fermi is
AIPMT 2012 Prelims
The transition from the state n = 3 to n = 1 in a hydrogen like atom results in ultraviolet radiation. Infrared radiatio...
AIPMT 2012 Mains
A mixture consists of two radioactive materials A1 and A2 with half lives of 20 s and 10 s respectively. Initially the ...
AIPMT 2012 Prelims
An electron in the hydrogen atom jumps from excited state n to the ground state. The wavelength so emitted illuminates a...
AIPMT 2011 Mains
Two radioactive nuclei P and Q, in a given sample decay into a stable nucleus R. At time t = 0. number of P species are ...
AIPMT 2011 Mains
Out of the following which one is not a possible energy for a photon to be emitted by hydrogen atom according to Bohr's ...
AIPMT 2011 Mains
Fusion reaction takes place at high temperature because
AIPMT 2011 Prelims
A nucleus $${}_n^mX$$ emits one $$\alpha$$ particle and two $$\beta$$ particles. The resulting nucleus is
AIPMT 2011 Prelims
A radioactive nucleus of mass M emits a photon of frequency $$v$$ and the nucleus recoils. The recoil energy will be
AIPMT 2011 Prelims
The power obtained in a reactor using U235 disintegration is 1000 kW. The mass decay of U235 per hour is ...
AIPMT 2011 Prelims
The half life of a radioactive isotope X is 50 years. It decays to another element Y which is stable. The two elements X...
AIPMT 2011 Prelims
The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series ...
AIPMT 2011 Prelims
The binding energy per nucleon in deuterium and helium nuclei are 1.1 MeV and 7.0 MeV, respectively. When two deuterium ...
AIPMT 2010 Mains
The decay constant of a radio isotope is $$\lambda$$. If A1 and A2 are its activities at times t1 and t2 respectively, ...
AIPMT 2010 Mains
An alpha nucleus of energy $${1 \over 2}$$ mv2 bombards a heavy nuclear target of charge Ze. Then the distance of close...
AIPMT 2010 Prelims
The energy of a hydrogen atom in the ground state is $$-$$ 13.6 eV. The energy of a He+ ion in the first excited state w...
AIPMT 2010 Prelims
The mass of a $${}_3^7Li$$ Li nucleus is 0.042 u less than the sum of the masses of all its nucleons. The binding energy...
AIPMT 2010 Prelims
The activity of a radioactive sample is measured as N0 counts per minute at t = 0 and N0/e counts per minute at t = 5 mi...
AIPMT 2010 Prelims
The energy of a hydrogen atom in the ground state is $$-$$ 13.6 eV. The energy of a He+ ion in the first excited state ...
AIPMT 2010 Prelims
The number of beta particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. Th...
AIPMT 2009
The ionization energy of the electron in the hydrogen atom in its ground state is 13.6 eV. The atoms are excited to high...
AIPMT 2009
In a Rutherford scattering experiment when a projectile of charge z1 and mass M1 approaches a target nucleus of charge z...
AIPMT 2009
In the nuclear decay given below $${}_Z^AX \to {}_{Z + 1}^AY \to {}_{Z - 1}^{A - 4}B{}^ * \to {}_{Z - 1}^{A - 4}B,$$ th...
AIPMT 2009
Two radioactive materials X1 and X2 have decay constants $$5\lambda$$ and $$\lambda$$ respectively. If initially they ...
AIPMT 2008
The ground state energy of hydrogen atom is $$-$$ 13.6 eV. When its electron is in the first excited state, its excitati...
AIPMT 2008
Two nuclei have their mass numbers in the ratio of 1 : 3. The ratio of their nuclear densities would be
AIPMT 2008
If M(A; Z), Mp and Mn denote the masses of the nucleus $${}_Z^AX,$$ proton and neutron respectively in units of u (1 u =...
AIPMT 2008
The total energy of electron in the ground state of hydrogen atom is $$-$$ 13.6 eV. The kinetic energy of an electron in...
AIPMT 2007
If the nucleus $${}_{13}^{27}Al$$ has a nuclear radius of about 3.6 fm, them $${}_{32}^{125}Te$$ would have its radius a...
AIPMT 2007
A nucleus $${}_Z^AX$$ has mass represented by M(A, Z). If Mp and Mn denote the mass of proton and neutron respectively a...
AIPMT 2007
In a mass spectrometer used for measuring the masses of ions, the ions are initially accelerated by an electric potentia...
AIPMT 2007
In a radioactive decay process, the negatively charged emitted $$\beta$$-particles are
AIPMT 2007
Two radioactive substances A and B have decay constants 5$$\lambda$$ and $$\lambda$$ respectively. At t = 0 they have ...
AIPMT 2007
The radius of germanium (Ge) nuclide is measured to be twice the radius of $${}_4^9$$Be. The number of nucleons in Ge ar...
AIPMT 2006
The binding energy of deuteron is 2.2 MeV and that of $${}_2^4$$He is 28 MeV. If two deuterons are fused to form one $${... AIPMT 2006 In a radioactive material the activity at time t1 is R1 and at a later time t2, it is R2. If the decay constant of the m... AIPMT 2006 Ionization potential of hydrogen atom is 13.6 eV. Hydrogen atoms in the ground state are excited by monochromatic radiat... AIPMT 2006 Energy levels A, B and C of a certain atom corresponding to increasing values of energy i.e. EA &lt; EB &lt; EC. If$$...
AIPMT 2005
Fission of nuclei is possible because the binding energy per nucleon in them
AIPMT 2005
In any fission process the ratio mass of fission products mass of parent nucleus is ...
AIPMT 2005
Which one of the following pairs of nuclei are isotones ?
AIPMT 2005
The total energy of an electron in the first excited state of hydrogen atom is about $$-$$ 3.4 eV. Its kinetic energy in...
AIPMT 2005
In the reaction $${}_1^2$$H + $${}_1^3$$H $$\to$$ $${}_2^4$$He + $${}_0^1$$n, if the binding energies of $${}_1^2$$ H,...
AIPMT 2005
The half life of radian is about 1600 years. Of 100 g of radium existing now, 25 g will remain unchanged after
AIPMT 2004
The Bohr model of atoms
AIPMT 2004
If in a nuclear fusion process the masses of the fusing nuclei be m1 and m2 and the mass of the resultant nucleus be m3,...
AIPMT 2004
A nucleus represented by the symbol $${}_Z^AX$$ has
AIPMT 2004
If M(A; Z), Mp and Mn denote the masses of the nucleus $${}_Z^AX,$$ proton and neutron respectively in units of u (1 u =...
AIPMT 2004
A nuclear reaction given by ZXA $$\to$$ z+1YA + $$-$$1e0 + $$\overline v$$ represents...
AIPMT 2003
In which of the following systems will the radius of the first orbit (n = 1) be minimum ?
AIPMT 2003
The mass number of a nucleus is
AIPMT 2003
The mass of proton is 1.0073 u and that of neutron is 1.0087 u (u = atomic mass unit). The binding energy of $${}_2^4$$ ...
AIPMT 2003
A sample of radioactive element has a mass of 10 g at an instant t = 0. The approximate mass of this element in the samp...
AIPMT 2003
The volume occupied by an atom is greater than the volume of the nucleus by a factor of about
AIPMT 2003
Solar energy is mainly caused due to
AIPMT 2003
An electron is moving round the nucleus of a hydrogen atom in a circular orbit of radius r. The Coulomb force $$\overrig... AIPMT 2003 A deutron is bombarded on 8O16 nucleus then$$\alpha $$-particle is emitted. The product nucleus is ... AIPMT 2002 A sample of radioactive element containing 4$$ \times $$1016 active nuclei. Half life of element is 10 days, then numb... AIPMT 2002 Which of the following are suitable for the fusion process ? AIPMT 2002 Energy released in nuclear fission is due to AIPMT 2001 The energy of hydrogen atom in nth orbit is En then the energy in nth orbit of singly ionised helium atom will be... AIPMT 2001 Mn and Mp represent the mass of neutron and proton respectively. An element having mass M has N neutrons and Z protons, ... AIPMT 2001 The interplanar distance in a crystal is 2.8$$ \times $$10$$-$$8 m. The value of maximum wavelength which can be diffr... AIPMT 2001 Half life of a radioactive element is 12.5 hour and its quantity is 256 g. After how much time its quantity will remain ... AIPMT 2001 X(n,$$\alpha $$)$${}_3^7$$Li, then X will be AIPMT 2001 Which rays contain (positive) charged particles ? AIPMT 2001 Maximum frequency of emission is obtained for the transition AIPMT 2000 The life span of atomic hydrogen is AIPMT 2000 The relation between$$\lambda $$and T1/2 as (T1/2$$ \to $$half life) AIPMT 2000 When an electron does transition from n = 4 to n = 2, then emitted line spectrum will be AIPMT 2000 Nuclear fission is best explained by AIPMT 2000 For the given reaction, the particle X is$$_6{C^{11}} \to {}_5{B^{11}} + {\beta ^ + } + X
AIPMT 2000

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