Question

Enter your answer in the provided box.

How much more energy per photon is there in green light of wavelength 536 nm than in red light of wavelength

622 nm?

__× 10 __ J
(Enter your answer in scientific notation.)

Answer 1

Answer : The correct answer is $5.20\times 10^{-20}J$

Explanation :

For green light :

$E=\frac{hC}{\lambda}$

where,

E = energy of green light = ?

h = Planck's constant = $6.626\times 10^{-34}Js$

C = speed of light = $3\times 10^8m/s$

$\lambda$ = wavelength of light = 536 nm = $536\times 10^{-9}m$

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

$E=\frac{(6.626\times 10^{-34}Js)\times (3\times 10^{8}m/s)}{536\times 10^{-9}m}$

$E=3.71\times 10^{-19}J$

For red light :

$E=\frac{hC}{\lambda}$

where,

E = energy of red light = ?

h = Planck's constant = $6.626\times 10^{-34}Js$

C = speed of light = $3\times 10^8m/s$

$\lambda$ = wavelength of light = 622 nm = $622\times 10^{-9}m$

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

$E=\frac{(6.626\times 10^{-34}Js)\times (3\times 10^{8}m/s)}{622\times 10^{-9}m}$

$E=3.19\times 10^{-19}J$

Now we have to calculate the energy difference.

$\text{Energy difference}=E_{green}-E_{red}$

$\text{Energy difference}=3.71\times 10^{-19}J-3.19\times 10^{-19}J=5.20\times 10^{-20}J$

Therefore, the correct answer is $5.20\times 10^{-20}J$