The Total solution for NCERT class 6-12
In the alpha-particle scatteringexperiment, if a thin sheet of solid hydrogen is used in place of a gold foil,then the scattering angle would not be large enough. This is because the massof hydrogen (1.67 × 10−27 kg) isless than the mass of incident α−particles (6.64 × 10−27 kg).Thus, the mass of the scattering particle is more than the target nucleus(hydrogen). As a result, the α−particles would not bounce back if solidhydrogen is used in the α-particle scattering experiment..
Rydberg’s formula is given as:
Where,
h = Planck’s constant = 6.6 × 10−34 Js
c = Speed of light = 3 × 108 m/s
(n1 and n2 are integers)
Theshortest wavelength present in the Paschen series of the spectral lines isgiven for values n1 = 3 and n2 = ∞.