a Compute the energies in J of a photon of light produced by

a) Compute the energies (in J) of a photon of light produced by: a solid state Nd:YAG laser with wavelength 1064 nm; an argon ion laser with wavelength 488 nm, and an excimer Xe-Cl laser with wavelength 308 nm. Which laser produces the most energetic photon?

b) What type of electromagnetic radiation does each of these wavelengths correspond to? If the answer is visible light, what is its color?

c) Which of these lasers produce pho tons of light with energy sufficient to break a chemical bond of energy 6x10-19J ?

Solution

(A) Photon energy E = hc/

h = plank constant = 6.626 x 10^-34 m² kg / s

c = speed of light = 3 x 10⁸ m/s

₁ =wavelength1 = 1064 x 10^-9 m

₂ =wavelength2 = 308 x 10^-9 m

E₁ = (6.626 x 10^-34 x 3 x 10⁸)/1064 x 10^-9 = 1.868 x 10^-19Joule

E₂ = (6.626 x 10^-34 x 3 x 10⁸)/308 x 10^-9 = 6.454 x 10^-19 Joule

(B)

Wavelength in visible spectrum is 390 - 700 nm. So both wavelengths are outside this range.

₁ =1064 nm, is near infrared region.

₂ =308 nm, is near ultraviolet region.

(C)

So clearly ₂ =308 nm has the more energy than 6x10^-19 J and will able to break chemical bond.