Question

A helium-neon laser can produce a green laser beam instead of a red one. The figure below shows the transitions involved to form the red beam and the green beam. After a population inversion is established, neon atoms make a variety of downward transitions in falling from the state labeled E4​ * down eventually to level E1​ (arbitrarily assigned the energy E1​=0 ). The atoms emit both red light with a wavelength of 632.8 nm in a transition E4​∗−E3​ and green light with a wavelength of 543 nm in a competing transition E4∗​−E2​. Use hc=1240 nm eV. (a) What is the energy E2​ ? eV

Answer 1

To find the energy level E2 of a neon atom in a helium-neon laser, use the energy formula E = hc/λ with the provided values, obtaining approximately 2.284 eV.

Step-by-step explanation:

The student has asked about the energy of a specific energy level (E2) in a neon atom within a helium-neon laser setup. To calculate the energy E2, we can use the given wavelength of the green light produced (543 nm) and the energy formula given by E = hc/λ, where h is Planck's constant, c is the speed of light in a vacuum, and λ is the wavelength of the emitted light. With hc provided as 1240 nm eV, we can find the energy in electronvolts (eV).

First, we convert the wavelength from nanometers to meters:

543 nm = 543 x 10-9 meters

Next, we compute the energy E2 using the formula:

E2 = hc/λ

E2 = (1240 eV nm) / (543 nm)

E2 = 2.284 eV (approximately)

Therefore, the energy level E2 is approximately 2.284 eV.

Answer 2

The energy E2 in a helium-neon laser is 0 eV.

Step-by-step explanation:

The energy of a photon emitted when neon goes from its metastable state to the one immediately below is 1.96 eV. To find the energy E2, we can use the equation E2 = E4* - E2*, where E4* is the energy of the metastable state and E2* is the energy of the state below it. Since E4* is equal to 1.96 eV, the energy E2 is 0 eV.