If a laser light is compose of photons each with an energy of 4.58 × 10−19 j, what is the photon energy of this light in units of nanometers, nm? report your answer with correct significant figures and correct units.

Answer : The photon energy of this light in units of nanometers, (nm) is,

Solution :

Formula used :

where,

E = energy of photon =

h = Planck's constant =

c = speed of light =

= wavelength = ?

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

conversion used :

Therefore, the photon energy of this light in units of nanometers, (nm) is,

the answer is d. 74.02