Question

What is the energy of one photon of light with a wavelength of 445 nm?

Answer 1

Answer : The energy of one photon of light is
`4.47* 10^(-19)J`

Explanation : Given,

Wavelength of photon =
`445nm=445* 10^(-9)m`

conversion used :
`1nm=10^(-9)m`

Formula used :

`E=h* \\u`

As,
`\\u=(c)/(\lambda)`

So,
`E=h* (c)/(\lambda)`

where,

`\\u` = frequency of photon

h = Planck's constant =
`6.626* 10^(-34)Js`

`\lambda` = wavelength of photon =
`445* 10^(-9)m`

c = speed of light =
`3* 10^8m/s`

Now put all the given values in the above formula, we get:

`E=(6.626* 10^(-34)Js)* ((3* 10^(8)m/s))/((445* 10^(-9)m))`

`E=4.47* 10^(-19)J`

Therefore, the energy of one photon of light is
`4.47* 10^(-19)J`