If the radius of first orbit of H atom is a₀ , the deBroglie wavelength of an electron in the third orbit is

Step-by-step solution

r_n=a₀ n^2 aligned & r=a₀ (3)^2=9 a₀ & m v r= n h 2 & m v= n h 2 r = 3 h 2 9 a₀ = h 6 a₀ & = h m v = h h 6 a₀=6 a₀ aligned