What is the energy in joules associated with a mole of photons that have a wavelength of 325 nm?

An electron in a hydrogen atom relaxes to the n = 4 level, emitting light at 138 THz. What is the initial energy level of the electron before relaxation?

Assuming that radiation with λ = 15.0 cm is used, that all the energy is converted to heat, and that 4.184 J is needed to raise the temperature of 1.00 g of water by 1.00 °C, how many photons are necessary to raise the temperature of 250 g of water by 1.00 °C?

Assuming that radiation with λ=15.0 cm is used, and that all the energy is converted to heat, with 4.184 J needed to raise the temperature of 1.00 g of water by 1.00 °C, how many photons are necessary to raise the temperature of a 300 g sample of water by 1.00 °C?

Assuming that radiation with λ = 15.0 cm is used, that all the energy is converted to heat, and that 4.184 J is needed to raise the temperature of 1.00 g of water by 1.00 °C, how many photons are necessary to raise the temperature of a 350 g sample of water by 1.00 °C?

Calculate the energy of the green light emitted, per photon, by a mercury lamp with a frequency of 5.49 × 10^14 Hz. Use Planck's constant (h = 6.626 × 10^-34 J·s).

Calculate the energy of the red light emitted by a neon atom with a wavelength of 680 nm. Use the formula E = hc/λ, where h is Planck's constant (6.626 x 10^-34 J·s) and c is the speed of light (3.00 x 10^8 m/s).

Calculate the energy of the violet light emitted by a hydrogen atom with a wavelength of 410.1 nm. Use the formula E = hc/λ, where h = 6.626 x 10^-34 J·s and c = 3.00 x 10^8 m/s.

Determine the energy, in joules per photon, of radiation with a frequency of 8.52 × 10^15 s⁻¹.