JEE Advanced2021ChemistryStructure of AtomActual
Consider a helium He atom that absorbs a photon of wavelength 330 nm . The change in the velocity (in cm s - 1 ) of He atom after the photon absorption is ______ . (Assume: Momentum is conserved when photon is absorbed. Use: Planck constant = 6 . 6 × 10 - 34 J s , Avocados number = 6 × 10 23 mol - 1 , Molar mass of He = 4 g mol - 1 )
Correct answer
0
Step-by-step solution
P = h λ mv = h λ v = h mλ v = 6 .6 × 10 − 34 × 6 × 10 23 4 × 10 − 3 × 330 × 10 − 9 v = 3 × 10 − 1   m / s v = 30   cm / s ∆ v   =   v f - v i = v - 0 = v   =   30   cm / s