List of top Physics Questions on Atoms and Nuclei

Assuming the experimental mass of $ {}^{12}_{6}\text{C} $ as 12 u, the mass defect of $ {}^{12}_{6}\text{C} $ atom is____MeV/$ c^2 $.
(Mass of proton = 1.00727 u, mass of neutron = 1.00866 u, 1 u = 931.5 MeV/$ c^2 $)

In the hydrogen atom, the electron makes a transition from the higher orbit ($i$) to a lower orbit ($f$). The ratio of the radius of the orbits in given by $r_i : r_f = 16 : 4$. The wavelength of photon emitted due to this transition is _________ nm. (Given Rydberg constant $= 1.097 \times 10^7 \text{ /m}$)

The binding energy per nucleon of $^{209} \text{Bi}$ is _______ MeV. \[ \text{Take } m(^{209} \text{Bi}) = 208.98038 \, \text{u}, \, m_p = 1.007825 \, \text{u}, \, m_n = 1.008665 \, \text{u}, \, 1 \, \text{u} = 931 \, \text{MeV}/c^2. \]

Angular momentum of an electron in a hydrogen atom is $ \dfrac{3h}{\pi} $. Then the energy of the electron is ____ eV.

An atom of lithium contains 3 electrons, 3 protons and 4 neutrons. Its mass number is:

Calculate the mass of an $\alpha$-particle in atomic mass unit (u).
Given: Mass of a normal helium atom = $ 4.002603 \ \text{u} $
Mass of carbon atom = $ 1.9926 \times 10^{-26} \ \text{kg} $

Assertion : In Bohr model of hydrogen atom, the angular momentum of an electron in $ n $th orbit is proportional to the square root of its orbit radius $ r_n $

Reason (R): According to Bohr model, electron can jump to its nearest orbits only.

The energy of an electron in a hydrogen atom in ground state is -13.6 eV. Its energy in an orbit corresponding to quantum number $ n $ is -0.544 eV. The value of $ n $ is:

Two nuclei with lower binding energy per nucleon form a nucleus with more binding energy per nucleon. (i) What type of nuclear reaction is it?

Show the variation of binding energy per nucleon with mass number. Write the significance of the binding energy curve.

The shortest wavelengths emitted in the hydrogen spectrum corresponding to different spectral series are:
(A) Pfund series
(B) Balmer series
(C) Brackett series
(D) Lyman series.
The wavelengths arranged correctly in decreasing order are_______.
Fill in the blank with the correct answer from the options given below.

As per Nuclear Physics, there is a close relationship between mass num ber and radius of the nucleus. If the mass number of A is 216 and the mass number of B is 27, then the ratio of nuclear radius $\frac{r_A}{r_B}$ of the two elements is:

Consider the following particles:
(A) Proton,
(B) α-particle,
(C) Electron.
For charge to mass ratio of the above particles, we can say:

The kinetic energy of an electron in the ground level in hydrogen atom is K units. The values of its potential energy and total energy respectively are_______
Fill in the blank with the correct answer from the options given below.

Two nuclei have mass numbers A and B respectively. The density ratio of the nuclei is______.
Fill in the blank with the correct answer from the options given below.

According to Bohr’s Model:
(A) The radius of the orbiting electron is directly proportional to ‘n’.
(B) The speed of the orbiting electron is directly proportional to 1/n. (C) The magnitude of the total energy of the orbiting electron isdirectly proportional to 1/n².
(D) The radius of the orbiting electron is directly proportional to n².

The study of radioactive decay results in the emission of particles, leading to four observations: (A) No change in atomic and mass number, (B) Atomic number decreases by 1, (C) Study of radioactive decay of unstable nuclei resulting in emission of a
particle leads us to four different observations listed below:
(A) Nochange in atomic number and mass number.
(B) Nochange in mass number but the atomic number decreases by 1.
(C) Nochange in mass number but the atomic number increases by 1.
(D) Atomic number decreases by 2 and the mass number decreases by 4.
Arrange the particles emitted in the above four cases in correct sequence:

An electron makes a transition from the $ n = 2 $ level to the $ n = 1 $ level in the Bohr model of a hydrogen atom. Its period of revolution: