Question

Find energy of each of the photons which

(i) correspond to light of frequency $3*10^{15}Hz$.
(ii) have wavelength of 0.50 Å.

NCERT Class XII
Chemistry - Main Course Book I

Chapter 2. Structure of Atom

Answer 1

E = h ν  = 6.626 * 10⁻³⁴ * 3  * 10¹⁵ = 1.9878 * 10⁻¹⁸  Joules
             = 12.423 eV   electron Volts

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ii)
   E = h v =  h c / λ  = 6.626 * 10⁻³⁴ * 2.98 * 10⁸ / 0.50 * 10⁻¹°
       =  3.843 * 10⁻¹⁵ Joules = 24 keV