Question

What is the energy of a photon of light having a wavelength of 4.5 x 10-7 meters? (Planck’s constant is 6.626 x 10-34 joule seconds; the speed of light is 2.998 x 108 m/s)



2.9817 x 10-40 joules



4.4143 x 10-19 joules



6.6745 x 10-26 joules second



9.9456 x 10-49 joules



19.864 x 10-26 joules/second

Answer 1

E = energy of photon = hc/lambda, where h is plank's constant, c is the speed of light, and lambda is the wavelength

make sure all units are consistent

Answer 2

energy E carried by a photon is given by the subsequent formula:
\[\Large E = h\nu \]
where \nu is the frequency of our photon, namely
\[\Large \nu = \frac{c}{\lambda }\]

Answer 3

c is the light speed

Answer 4

\lambda is the wavelength

Answer 5

@briannaboswell:

energy of photon = E
c = speed of light = 2.998*10^8
lambda = wavelength = 4.5 x 10-7 m
h = plank's constant = 6.626 x 10-34

E = h*c/(lambda)

all you have to do is plug in the values of h, c, and lambda...

Answer 6

so, substituting, we can write:
\[\Large E = \frac{{hc}}{\lambda } = \frac{{6.62 \times {{10}^{ - 34}} \times 3 \times {{10}^8}}}{{4.5 \times {{10}^{ - 7}}}} = ...Joules\]