The manifestation of band structure in solids is due to
Heisenberg’s uncertainty principle
Pauli’s exclusion principle
Bohr’s correspondence principle
Boltzmann’s law
In terms of Bohr radius a0, the radius of the second Bohr orbit of hydrogen atom is given by
4 a0
8 a0
√2 a0
2 a0
The energy required to excite hydrogen atom from n = 1 to n = 2 state is 10.2 eV. What is the wavelength emitted when it returns to ground state?
1020 × 10-10 m
1220 × 10-10 m
1320 × 10-10 m
920 × 10-10 m
In a Rutherford scattering experiment when a projectile of charge Z1and mass M1 approaches a target nucleus of charge Z2 and Mass M2, the distance of closest approach is r0. The energy of the projectile is
Directly proportional to M1 × M2
Directly proportional to Z1 Z2
Inversely proportional to Z1
Directly proportional to Mass M1
If 13.6 eV energy is required to ionize the hydrogen atom, then the energy required to remove an electron from n = 2 is
102 eV
Zero
-3.4 eV
6.8 eV
Which of the following transitions in a hydrogen atom emits off the highest frequency?
n = 1 to n = 2
n = 2 to n = 6
n = 2 to n = 1
n = 6 to n = 2
An α-particle of energy 5 MeV is scattered through 180o by a fixed uranium nucleus. The distance of the closest approach is of the order of
1 Å
10-10 cm
10-12 cm
10-15 cm
The spectrum obtained from a sodium vapour lamp is an example of
Band spectrum
Continuous spectrum
Emission spectrum
Absorption spectrum
The Bohr model of atoms
Assumes that the angular momentum of electrons is quantized
Uses Einstein’s photoelectric equationÂ
Predict continuous emission spectra for atoms
Predicts the same emission spectra for all types of atoms
Hydrogen atom emits blue light when it changes from n = 4 energy level to n = 2 level. Which colour of light would the atom emit when it changes from n = 5 level to n = 2 level?
Red
Yellow
Violet
Green
