The frequency of the series limit of the Balmer series of hydrogen atoms in terms of Rydberg constant R and velocity of light C is:
1.
2. RC
3.
4. 4RC
The energy of an electron in an excited hydrogen atom is -3.4 eV.
Its angular momentum will be:
(h = 6.626 10-34 J-s)
1. 1.11 1034 J s
2. 1.51 10-31 J s
3. 2.11 10-34 J s
4. 3.72 10-34 J s
As per the Bohr model, the minimum energy (in eV) required to remove the electron from the ground state of a double ionised lithium ion (Z = 3) is:
1. 1.51
2. 13.6
3. 40.8
4. 122.4
The ionisation energy of a hydrogen atom is 13.6 eV. Following Bohr's theory, what is the energy corresponding to a transition between the 3rd and 4th orbit?
1. 3.40 eV
2. 1.51 eV
3. 0.85 eV
4. 0.66 eV
The energy of 24.6 eV is required to remove one of the electrons from a neutral helium atom. What is the energy (in eV) required to remove both the electrons from a neutral helium atom?
1. 38.2
2. 49.2
3. 51.8
4. 79.0
The radius of a hydrogen atom in its ground state is 5.3×10-11 m. After collision with an electron, it is found to have a radius of 21.2 ×10-11 m. What is the principal quantum number n of the final state of the atom?
1. n = 4
2. n = 2
3. n = 16
4. n = 3
A hydrogen atom is in an excited state of principal quantum number (n). It emits a photon of wavelength () when it returns to the ground state. The value of n is:
1.
2.
3.
4. None of these
The given diagram indicates the energy levels of a certain atom. When the system moves from the 2E level to E, a photon of wavelength λ is emitted. What is the wavelength of the photon produced during its transition from the level to E?
1.
2.
3.
4.
The wavenumber of a photon in the Brackett series of a hydrogen atom is . What is the quantum number of the electron that has transited from the orbit?
1. 5
2. 6
3. 4
4. 7
Hydrogen 1H1, Deuterium 1H2, singly ionised helium (2He4)+, and doubly ionised lithium (3Li6)++ all have one electron around the nucleus. Consider an electron transition from n = 2 to n = 1. If the wavelengths of emitted radiations are λ1 ,λ2 ,λ3 and λ4 respectively, then approximately which one of the following is correct?
1. | \(4 \lambda_1=2 \lambda_2=2 \lambda_3=\lambda_4\) |
2. | \( \lambda_1=2 \lambda_2=2 \lambda_3=\lambda_4\) |
3. | \( \lambda_1=\lambda_2=4 \lambda_3=9\lambda_4\) |
4. | \( \lambda_1=2\lambda_2=3 \lambda_3=\lambda_4\) |