Atoms and Nuclei

A nucleus of uranium -235 absorbs a slow neutron and undergoes nuclear fission according to the reaction: ${ }_{92}^{235} U+{ }_0^1 n \rightarrow{ }_{56}^{141} B a+{ }_{36}^{92} K r+3{ }_0^1 n+Q$
If the average energy released per fission i...

A mercury-198 nucleus is bombarded by a neutron, which causes a nuclear reaction
\(n_0^1+\mathrm{Hg}_{80}^{198} \longrightarrow A u_{79}^{197}+X\)
What is the unknown product particle $X$ ?

An atom with one electron has ionization energy of 24 eV . An electron in this atom makes a transition from an excited energy level, where $\mathrm{E}=-15 \mathrm{eV}$, to the ground state. What is the wavelength of the emitted photon from ...

Two deuterons are fused to form one alpha particle. If binding energy per nucleon of deuterium is 1.05 MeV and that of alpha particle is 7 MeV , what is the energy released in the formation of one alpha particle from the fusing of two deute...

An atom has a single electron. Its ground state energy is -30 eV and its first excited state energy is -8 eV . The atom is bombarded with a stream of photons, each of energy 15 eV .
Assuming the atom being in the ground state, which of the ...

A hydrogen atom absorbs energy and rises to $n=3$ state from its ground state $n=1$. If the potential energy of the atom at its ground state is -13.6 eV , find the wave length emitted by it when it returns to its ground state:
{Planck's con...

If the ratio of the nuclear radii of two atoms is $2: 3$ then the ratio of their mass numbers is:

The atomic mass of an element $10 X^{20}$ is 19.98170 amu. The binding energy per nucleon of that element is: [given mass of neutron = 1.00867amu and mass of proton = 1.00783 amu and 1amu = 931 MeV ]

The main function of cadmium used in the nuclear reactor is:

What is the frequency of the electron in the first orbit of hydrogen atom of orbital radius $0.5 \times 10^{-10} \mathrm{~m}$, if its orbital velocity in that orbit is $2.2 \times 10^6 \mathrm{~ms}^{-1}$.

Which, of the following is true of the Balmer series of the hydrogen spectrum?
a. The series is in the visible region.
b. The entire series falls in the ultraviolet region
c. The entire series falls in the infrared region
d. The series is p...

According to Bohr's theory of hydrogen atom, the speed of the electron, its energy and radius of its orbit vary with the principal quantum number $n$, respectively as

In a nuclear fusion reaction, two nuclei, $A$ and $B$ fuse to produce a nucleus $C$, releasing an amount of energy $\Delta \mathrm{E}$ in the process. If the mass defects of the three nuclei are $\Delta M_A, \Delta M_B$ and $\Delta M_C$ res...

Radium having mass number 200 and binding energy per nucleon 5.6 MeV , splits into two fragments Cadmium of mass number 112 and Hassium of mass number 108. If the binding energy per nucleon for Cadmium and Hassium is approximately 8.0 MeV ,...

If the mass numbers of two nuclei are in the ratio $5: 2$ and their diameters are in ratio $2: 6$. Then their nuclear densities will be in the ratio

When ${ }^{10} \mathrm{~B}_5$ nuclei are bombarded by neutrons, one of the resultant nuclei is ${ }^7 \mathrm{Li}_3$. Then the emitted particle will be:

The minimum energy required by a hydrogen atom in ground state to emit radiation in Paschen series is nearly:

Which of the following is correct in the case of the Bohr model of atoms?
A. Predicts continuous emission spectra for all atoms
B. Assumes that the angular momentum of electrons is quantised
C. Predicts same emission spectrum for singly ion...

Select the correct statement from the following:

The nucleus of oxygen atom contains 8 protons and 8 neutrons. What is the mass defect in amu?
[Given Mass of proton $=1.00727 \mathrm{amu}$ Mass of neutron $=1.00866 \mathrm{amu}$ and the mass of oxygen nucleus $=15.99053 \mathrm{amu}$. ]

To get 300 MW electric power for half an hour, how much mass is to be completely converted into energy?

Fusion reaction is more energetic than fission reaction because

What is the frequency ' $\nu$ ' of the electron in Bohr's first orbit of radius ' $r$ ' of the hydrogen atom?

Find the binding energy of the tritium nucleus:
[Given: mass of \(1 \mathrm{H}^3=3.01605 \mathrm{~u} ; \mathrm{~m}_{\mathrm{p}}=1.00782 \mathrm{~u} ; \mathrm{~m}_{\mathrm{n}}=1.00866 \mathrm{~u}\).]

The closest approach of an alpha particle when it make a head on collision with a gold nucleus is \(10 \times 10^{-14} \mathrm{~m}\), then the kinetic energy of the alpha particle is :

The ratio of the radii of the nucleus of two element \(\mathrm{X}\) and \(\mathrm{Y}\) having the mass numbers 232 and 29 is:

\(\text { If the nuclear radius of }{ }^{27} \mathrm{Al} \text { is } 3.6 \text { fermi, the nuclear radius of }{ }^{125} \mathrm{Fe} \text { is }\)

An electron has a mass of \(9.1 \times 10^{-31} \mathrm{~kg}\). It revolves round the nucleus in a circular orbit of radius \(0.529 \times 10^{-10} \mathrm{~m}\) at a speed of \(2.2 \times 10^6 \mathrm{~ms}^{-1}\). The magnitude of its angu...

If an electron in a hydrogen atom jumps from the third orbit to the second orbit, it emits a photon of wavelength \(\lambda\). When it jumps from the second to the first orbit, the corresponding wavelength of the photon will be

The binding energy per nucleon for \(\mathrm{C}^{12}\) is \(7.68 \mathrm{~MeV}\) and that for \(\mathrm{C}^{13}\) is \(7.47 \mathrm{~MeV}\). The energy required to remove a neutron from \(\mathrm{C}^{13}\) is

The distance of closest approach when an alpha particle of kinetic energy \(6.5 \mathrm{~MeV}\) strikes a nucleus of atomic number 50 is

The shortest wavelengths of Paschen, Lymen and Balmer series are in the ratio

A nucleus with mass number 190 initially at rest emits an alpha particle. If the \(\mathrm{Q}\) value of the reaction is \(4.5 \mathrm{~MeV}\), the kinetic energy of the alpha particle is

In a hydrogen atom, if electron is replaced by a particle which is 40 times heavier but has the same charge, then, the ratio of the radius of the first excited state of a normal hydrogen atom to the ground state of the above atom is

The radius of a nucleus as measured by electron scattering is \(4.8 \mathrm{~fm}\). The mass number of nucleus is most likely to be

Which of the following statement is true when a gamma decay occurs from the nucleus of an atom?

In the head-on collision of two alpha particles \(\alpha_1\) and \(\alpha_2\) with the gold nucleus, the closest approaches are 31.4 fermi and 94.2 fermi respectively. Then the ratio of the energy possessed by the alpha particles $$\alpha_2...

The ground state energy of hydrogen atom is \(-13.6 \mathrm{~eV}\). If the electron jumps from the \(3^{\text {rd }}\) excited state to the ground state then the energy of the radiation emitted will be:

A particle at rest decays in to two particles of mass \(m_1\) and \(m_2\) and move with velocities \(v_1\) and \(v_2\). The ratio of their de Broglie wave length \(\frac{\lambda_1}{\lambda_2}\) is:

In a nuclear reaction 2 deuteron nuclei combine to form a helium nucleus. The energy released in \(\mathrm{MeV}\) will be: (Given mass of deuteron \(=2.01355 \mathrm{~amu}\). and mass of helium nucleus \(=4.0028 \mathrm{~amu}\).

The mass number of two nuclei \(\mathrm{P}\) and \(\mathrm{Q}\) are 27 and 125 respectively. The ratio of their radii \(R_P: R_Q\) is given by:

The first emission of hydrogen atomic spectrum in Lyman series appears at a wavelength of

The wavelength of the first line of Lyman series for \(\mathrm{H}\) - atom is equal to that of the second line of Balmer series for a \(\mathrm{H}\)-like ion. The atomic number \(\mathrm{Z}\) of \(\mathrm{H}\)-like ion is

The mass density of a nucleus varies with mass number \(A\) as

The wavelength of the second line of Balmer series is 486.4 nm. What is the wavelength of the first line of Lyman series?

Which of the following series spectrum of hydrogen atom lies in ultraviolet region?

During \(\alpha\)-decay, atomic mass of parent nuclei is

When the speed of light becomes \(\frac{2}{3}\) of its present value, then the energy released in a given atomic explosion would

Ba-122 has half-life of 2 min. Experiment has to be done using Ba-122 and it takes 10 min to set up the experiment. It initially 80 g at Ba-122 was taken, how much Ba was left when experiment was started?

If an electron in hydrogen atom jumps from an orbit of level \(n=3\) to an orbit at level \(n=2\), emitted radiation has a frequency of
(R = Rydberg's constant and c = velocity of light)