NEET-XII-Physics
43: Bohr's Model and Physics of the Atom
- #4Evaluate Rydberg constant by putting the values of the fundamental constants in its expression.Ans : Expression of Rydberg constant (R) is given by
`` R=\frac{m{e}^{4}}{8{h}^{2}c{\in }_{0}^{2}}``
Mass of electron, me = 9.31`` \times ``1021 kg
Charge, e = 1.6 × 10-19 C
Planck's constant, h = 6.63 × 10-34 J-s,
Speed of light, c = 3 × 108 m/s,
Permittivity of vacuum, ∈0 = 8.85 × 10-12 C2N`` -1``m
On substituting the values in the expression, we get
`` R=\frac{\left(9.31\times {10}^{-31}\right)\times {\left(1.6\times {10}^{-19}\right)}^{4}}{8\times {\left(6.63\times {10}^{-34}\right)}^{2}\times \left(3\times {10}^{8}\right)\times {\left(8.85\times {10}^{-12}\right)}^{2}}``
`` \Rightarrow R=1.097\times {10}^{7}{\,\mathrm{\,m\,}}^{-1}``
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