Atom, origin of spectra Bohr's theory of hydrogen atom
1. IMPORTANT THEORY QUESTIONS
Atom, Origin of Spectra : Bohr's Theory of Hydrogen Atom
Prepared by : Mukesh N Tekwani
Email: scitechgen@outlook.com
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Marks Keyword(s)
1 Describe Rutherford’s ∝-particle scattering experiment. Why was an
extremely thin gold foil used in this experiment?
3 Rutherford’s
expt
2 What is Rutherford’s model of atom? What are the drawbacks of this
model?
3 Rutherford’s
model
3 Explain the significance of ‘distance of closest approach’ of ∝-particles to
atomic nuclei.
2 Rutherford’s
expt
4 On the basis of ∝-particle scattering experiment, obtain an expression for
the upper limit of the radius of the scattering nuclei in terms of atomic
number Z and energy K of the incident ∝-particles.
3 Derive
5 Explain how Rutherford’s model of atom failed to explain the existence of
sharp lines in the hydrogen spectrum. How was this difficulty removed by
Bohr?
3 Rutherford’s
model
6 State Bohr’s postulates. Derive an expression for the stationary energy
levels of an electron in the hydrogen atom. State the significance of the
negative sign in the energy equation.
3 Bohr’s model
7 Derive an expression for the kinetic energy of an electron in the Bohr model
of hydrogen atom.
3 Derive
8 What are the limitations of Bohr’s theory? 5 Bohr’s theory
9 Draw the energy level diagram for hydrogen atom. Show transitions for
Lyman, Balmer, Paschen, Brackett and Pfund series.
5 Diagram
10 How is line spectrum explained on the basis of emission of light? 3 Line spectrum
11 How is line spectrum explained on the basis of absorption of light? 3 Line spectrum
12 What is Bohr’s quantization condition? 2 Bohr’s model
13 What is Rydberg constant? State its unit. 1 Rydberg
constant
14 Define excitation potential of an atom. Do atoms have one or more
excitation potential?
1 Define
15 Define ionisation potential of an electron. 1 Define
(c)M
ukesh
N
Tekw
ani
