Question

What is the energy in electron-volts (eV) of a photon of green light that has a wavelength of 520 nm? (1.0 m = 1.0 × 10^-9m)

3.8 × 10^-19eV
3.4 × 10^-40eV
2.4eV
2.2 × 10^-21eV

Answer 1

The energy of a photon is
`3.8*10^(-19)\ eV`.

Step-by-step explanation:

Given that,

Wave length = 520 nm

`1 nm = 1* 10^(-9)\ m`

Using plank's equation

`E =h\\u`...(I)

Here, h = plank constant

υ = frequency

Now, using wave equation

`c =\lambda* \\u`

The equation can be written as:

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

Here, c = speed of light

λ= wave length of light

Put the value of υ in equation (I)

The energy of photon is

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

`E = (6.63*10^(-34)*3*10^(8))/(520*10^(-9))`

`E=3.8*10^(-19)\ eV`

Hence, The energy of a photon is
`3.8*10^(-19)\ eV`.