Find the ratio ofenergy of a photon of ` 2000Å` wavelength radiation to that of ` 400Å` wavelength radiation to that of `4 000Å` radiation .

Answer

2

Explanation

`E = (hc)/( lambda) i.e., E prop 1/( lambda)`
`:.E_1/E_2 = ( lambda_2)/( lambda_1) = (4000)/(2000)=2`.