# A photon has an energy of 2.93 X 10-25 J. What is its wavelength?

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### 1 Answer

The energy is related to wavelength as

`E = (hc)/lambda`

where, h is the Planck's constant (6.626 x 10^-34 J s) and c is the speed of light in vacuum (3 x 10^8 m/s)

Thus, the wavelength can be calculated as:

wavelength = hc/E

= `(6.626 xx 10^(-34) xx 3 xx 10^8)/(2.93 xx 10^-25)`

= **0.678 m**

Hope this helps.