The wavelength of coherent ruby laser light is 694 nm.What energy difference exists between the upper excited state involved and the lower unexcited ground state? (h = 6.63 × 10−³⁴ J⋅s,c = 3.00 × 10⁸ m/s,1 eV = 1.60 × 10−¹⁹ J,and 1 nm = 10−⁹ m) A)0.56 eV B)1.79 eV C)1.67 eV D)2.87 eV E)0.35 eV

Question

Quizplus · Accepted Answer

The energy difference between the upper excited state and the lower unexcited ground state can be calculated using the formula:

ΔE = hc/λ

where h is Planck's constant, c is the speed of light, and λ is the wavelength of the radiation.

Substituting the given values, we get:

ΔE = (6.63 × 10^-34 J·s) x (3.00 × 10^8 m/s) / (694 × 10^-9 m) = 2.87 x 10^-19 J

Converting this to electron volts (eV), we get:

ΔE = (2.87 x 10^-19 J) / (1.60 × 10^-19 J/eV) = 1.79 eV

Therefore, the answer is B.

The Wavelength of Coherent Ruby Laser Light Is 694 Nm