The radius of the first permitted Bohr orbit for the electron in a hydrogen atom equals \(0.5~\mathring{\text{A}}\) and its ground state energy equals \(-13.6~\text{eV}\). If the electron in the hydrogen atom is replaced by a muon \((\mu^{-})\) [charge same as electron and mass \(207~m_e\)], the first Bohr radius and ground state energy will be: ( \(m_e\) represents the mass of an electron)
1. | \(0.53\times10^{-13}~\text{m}, ~-3.6~\text{eV}\) |
2. | \(25.6\times10^{-13}~\text{m}, ~-2.8~\text{eV}\) |
3. | \(2.56\times10^{-13}~\text{m}, ~-2.8~\text{keV}\) |
4. | \(2.56\times10^{-13}~\text{m}, ~-13.6~\text{eV}\) |
An electron in Bohr's hydrogen atom has angular momentum . The energy of the electron is
1. -3.4 eV
2. -0.64 eV
3. -0.85 eV
4. -10.25 eV
If the energy of the electron in an \(\mathrm{H}\)-atom in the ground state is taken to be \(-13.6\) eV, then the kinetic energy of the electron in the first excited state will be:
1. \(3.4\) eV
2. \(6.8\) eV
3. \(10.2\) eV
4. \(13.6\) eV
An electron and a proton are separated by a large distance. The electron starts approaching the proton with energy 2eV. The proton captures the electron and forms a hydrogen atom in first excited state. The resulting photon is incident on a photosensitive metal of threshold wavelength 4600Å. The maximum K.E. of the emitted photoelectron is (Take hc = 12420 eV Å)
1. 2.4 eV
2. 2.7 eV
3. 2.9 eV
4. 5.4 eV
\(\alpha\text{-}\)particle consists of:
1. | \(2\) protons only |
2. | \(2\) protons and \(2\) neutrons only |
3. | \(2\) electrons, \(2\) protons, and \(2\) neutrons |
4. | \(2\) electrons and \(4\) protons only |
The total energy of an electron in the orbit of an atom is \(-3.4~\mathrm{eV}\). Its kinetic and potential energies are, respectively:
1. | \(3.4~\mathrm{eV},~3.4~\mathrm{eV}\) |
2. | \(-3.4~\mathrm{eV},~-3.4~\mathrm{eV}\) |
3. | \(-3.4~\mathrm{eV},~-6.8~\mathrm{eV}\) |
4. | \(3.4~\mathrm{eV},~-6.8~\mathrm{eV}\) |
The radius of Germanium (Ge) nuclide is measured to be twice the radius of . The number of nucleons in Ge is:
1. 73
2. 74
3. 75
4. 72
In a discharge tube ionization of enclosed gas is produced due to collisions between:
1. positive ions and neutral atoms/molecules
2. negative electrons and neutral atoms/molecules
3. photons and neutral atoms/molecules
4. neutral gas atoms/molecules
If the nucleus has a nuclear radius of about 3.6 fermis, then would have its radius approximately as:
1. 6.0 Fermi
2. 9.6 Fermi
3. 12.0 Fermi
4. 4.8 Fermi