**Question 2.6: Find the energy of each of the photons**

**Question 2.6: Find the energy of each of the photons which**

**(i) corresponds to light of frequency 3× 10 ^{15} Hz.**

**(ii) have a wavelength of 0.50 Å.**

**Ans 2.6. We know**

**(i) Energy (E) of a photon (E) = hν —————–A**

Where, h = Planck’s constant = 6.626 × 10^{–34} Js

ν = frequency of light = 3 × 10^{15} Hz

ν = 3 × 10^{15} s^{–1}

Substituting the values of h and ν in expression A

E = (6.626 × 10^{–34}) (3 × 10^{15})

E = 1.988 × 10^{–18} J

**(ii) Energy (E) of a photon having wavelength (λ)is given as**

E = hc/λ ———————–A

h = Planck’s constant = 6.626 × 10^{–34} Js

λ = 0.50 × 10^{-10}m

c = velocity of light in vacuum = 3 × 10^{8} m/s

Substituting the values in the relation A

E = (6.626 × 10^{–34}) × 3 × 10^{8}/ 0.50 × 10^{-10}m

E = 3.98 × 10^{-15 }J.

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