A blue-light photon has a wavelength of

4.80 * 10^-7 meter. What is the energy of the

photon?

(1) 1.86 * 10^22 J (3) 4.14 * 10^-19 J

(2) 1.44 * 10^2 J (4) 3.18 * 10^-26 J

Energy = hc/λ, where h is planck's constant, c is the speed of light and λ is the wavelength.

Energy = (6.626 x 10^-34*3.00 x 10^8) / (4.80 * 10^-7) = 4.14*10^-19 J, which is 3.

Normally, when solving these equations, don't forget to check the units are correct (eg. wavelength is in meters) and dont forget to include the units in the calculation.