A laser emits photons having an energy of 3.74 × 10–19 J. What color would be expected for the light emitted by this laser? (c = 3.00 × 108 m/s, h = 6.63 × 10–34 J ⋅ s)

The wavelength of the emitted photons 532 nm, corresponds to a visible light having GREEN color.

Explanation:

Given;

energy of the emitted photons, E = 3.74 x 10⁻¹⁹ J

speed of light, c = 3 x 10⁸ m/s

Planck's constant, h = 6.63 x 10⁻³⁴ J.s

The wavelength of the emitted light will be calculated by applying energy of photons;

where;

E is the energy emitted light

h is Planck's constant

f is frequency of the emitted photon

But f = c / λ

where;

λ is the wavelength of the emitted photons

λ ≅ 532 nm

the wavelength of the emitted photons is 532 nm.

Therefore, the wavelength of the emitted photons 532 nm, corresponds to a visible light having GREEN color.

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.