Question

What is the energy of a single photon of infrared light with a wavelength of 1.00 µm? 1 µm = 10^-6m

Answer 1

Energy is found as:

E = 1.987·10⁻¹⁹ J

Step-by-step explanation:

Energy of a single photon of infrared light can be found by using the following formula:

`E=hf`

where

E = in Joules

h = Planck's constant = 6.627×10 ⁻³⁴ J

f = frequency in hertz

It can also be written as:

`E = (hc)/(\lambda)`

where

c = 2.998×10⁸ ms⁻¹

λ = wavelength

Wavelength is given in the question which is:

λ = 1×10⁻⁶m

Substitute all the values in the Energy formula

`E = (hc)/(\lambda)\\E = ((6.627\cdot10^(-34))(2.998\cdot10^8))/(1\cdot10^(-6))\\E = 1.987\cdot10^(-19)J`