Everything Science Grade 12

CHAPTER 15. EM RADIATION 15.5

Example 4: Calculating the energyof a photon II

QUESTION

What is the energy of anultraviolet photon witha wavelength of 200 nm?

SOLUTION

Step 1 : Determine what is required and how to approach the problem.

We are required to calculate the energy associated with a photon

of ultraviolet light with awavelength of 200 nm.

We can use:

E = h

c

λ

Step 2 : Solve the problem

E = h

c

λ

= (6, 626 × 10 −^34 )

3 × 108

200 × 10 −^9

= 9, 939 × 10 −^10 J

Exercise 15 - 4

1. How is the energy ofa photon related to its frequency and wavelength?


2. Calculate the energyof a photon of EM radiation with a frequency of 1012 Hz.


3. Determine the energy of a photon of EM radiation with a wavelengthof 600 nm.

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