Visible light has wavelengths in the range of 400 nm to 780nm. Calculate the range of energy of the photons of visible light.

Explanation

We have `lambda_1 = 400 nm` to `lambda_2 = 780 nm `
h `=6.63 xx 10^(-34) J-s` ,
`d = 3 xx 10^(5) m/s `
` E_1 = hc / lambda_1 `
` = 6.63 xx 10^(-34) xx 3 xx 10^(8) / 400 xx 10^(-9)`
`= 6.63 xx 3 / 4 xx 10^(-9)`
` = 4.977245 xx 10^(-19) `
` 5 xx 10^(-19) J `
` E_2 = 6.63 xx 3 / 7.8 xx 10^(-19) `
`= 2.55 xx 10^(-19)J`
So, the range is `2.55 xx 10^(-19) J to 5 xx 10^(-19)`