The orbital speed of an electron in a hydrogen atom, is given by the relation

v₁ =

or v₁ =

where ε₀ is the absolute permittivity of free space and is given as = 8.854 × 10^-12 N^-1C²m^-2

h is Planck’s constant and is given as 6.64 × 10^-34 Js

substituting the values, we get

v₁ =

On calculating, we get

v₁ = 0.0218 × 10⁸ m/s

Or v₁ = 2.18 × 10⁶ m/s

For n = 2

or v₂ =

substituting the values, we get

On calculating, we get

v₂ = 1.09 × 10⁶ m/s

Similarly, for n = 3, we get

or v₃ =

substituting the values, we get

On calculating, we get

v₃ = 7.27 × 10⁶ m/s