9. Quantum Mechanics

What is the wavelength in nanometers of light with a frequency of 7.8 × 10^15 Hz?

What is the wavelength of light emitted (in nm) when the electron in a hydrogen atom moves from n=4 to n=2?

If the frequency of electromagnetic radiation is 1.22 x 10^15 Hz, what is the wavelength of this radiation?

What is the wavelength, in nanometers, of a photon with 5.11 × 10⁻¹⁹ J of energy?

What must be the velocity, in meters per second, of a beam of electrons if they are to display a de Broglie wavelength of 880 nm?

What is the wavelength of 7000 Å in nanometers (nm)?