Question

The energy of a photon of radiation having wavelength 3000A˚ is nearly:

A)6.63×10^-19J

B)6.63×10^-18J

C)6.63×10^-16J

D)6.63×10^-49J



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Answer 1

Answer:-

6.63 × 10⁻¹⁹ J [Option. A]

Explanation:-

Firstly, let's convert the wavelength of the photon from Å to m.

=> 1 Å = 10⁻¹⁰ m

=> 3000 Å = 3000(10⁻¹⁰)

=> 3000×10⁻¹⁰ m

• Speed of light = 3×10⁸ m/s

We know that :-

ν = c/λ

Where :-

• ν is the frequency.

• c is the speed of light.

• λ is wavelength.

=> ν = 3×10⁸/3000×10⁻¹⁰

=> ν = 1×10⁸/1×10⁻⁷

=> ν = 10¹⁵ s⁻¹

• Planck's constant = 6.625×10⁻³⁴ Js

Now, energy of the photon :-

E = hν

Where:-

• E is energy.

• h is Planck's constant.

• ν is frequency.

=> E = 6.625×10⁻³⁴×10¹⁵

=> E = 6.625×10⁻¹⁹ J ≈ 6.63×10⁻¹⁹ J

Thus, energy of the photon

is 6.63×10⁻¹⁹J