How much energy is in a yellow light with a wavelength of 525nm?
Answers
Explanation:
The energy of a photon is proportional to its frequency, as stated by the Planck - Einstein's equation
E
=
h
⋅
ν
, where
E
- the energy of the photon
h
- Planck's constant, equal to
6.626
⋅
10
−
34
J s
ν
- the frequency of the photon
Now, notice that you are given the wavelength of the photon,
λ
. As you know, frequency and wavelength have an inverse relationship described by the equation
λ
⋅
ν
=
c
, where
c
- the speed of light in vacuum, approximately equal to
3
⋅
10
8
m s
−
1
This means that the relationship between energy and wavelength looks like this
λ
⋅
ν
=
c
⇒
ν
=
c
λ
E
=
h
⋅
c
λ
Another important thing to notice here is that the wavelength of the photon is given in nanometers,
nm
. You need to convert this to meters, the unit used for the value of the speed of light.