An electron in the hydrogen atom makes a transition from an energy state of principal quantum number $n_1$ to the n = 2 states. If the photon emitted has a wave length of 434 nm, what is the value of $n_1$?

Calculate the frequency (Hz) and wavelength (nm) of the emitted photon when an electron drops from the n = 4 to the n = 2 level in a hydrogen atom.

When light of frequency equal to 2.11$\times 10^{15} \mathrm{~s}^{-1}$ shines on the surface of gold metal, the kinetic energy of ejected electrons is found to be 5.83$\times 10^{-19}$J. What is the work function of gold?

Calculate the frequency (Hz) and wavelength (nm) of the emitted photon when an electron drops from the $n=4$ to the $n=3$ level in a hydrogen atom.

Explain how astronomers are able to tell which elements are present in distant stars by analyzing the electromagnetic radiation emitted by the stars.

The first line of the Balmer series occurs at a wave length of $656.3$ $\mathrm{nm}$. What is the energy difference between the two energy levels involved in the emission that results in this spectral line?

Some copper compounds emit green light when they are heated in a flame. How would you determine whether the light is of one wavelength or a mixture of 2 or more wavelengths?

Explain how astronomers are able to tell which elements are present in distant stars by analyzing the electromagnetic radiation emitted by the stars.

Calculate the frequency and wavelength of the emitted photon when an electron drops from the "n=4" to the "n=2" level in a hydrogen atom.

The first line of the Balmer-series occurs at a wavelength of 656.3 nm. What is the energy difference between the two energy levels involved in the emission that results in this spectral line?

What is the wavelength, in nm, of radiation that has an energy content of 1.0 $\times 10^3$ kJ/mol? In which region of the electromagnetic spectrum is this radiation found?

The blue color of the sky results from the scattering of sunlight by one of the components of air. The blue light has a frequency of about $7.5 \times 10^{14} \mathrm{~Hz}$. Calculate the wavelength (in $\mathrm{nm}$ ) associated with this radiation

A particular form of electromagnetic radiation has a frequency of $8.11 \times 10^{14} \mathrm{~Hz}$.
(a) What is its wavelength in nanometers? In meters?
(b) To what region of the electromagnetic spectrum would you assign it?
(c) What is the energy (in joules) of one quantum of this radiation?

The $\mathrm{SI}$ unit of length is the meter, which corresponds to the length equal to $1,650,763.73$ wavelengths of the light emitted by a particular energy transition in krypton$-86$ atoms. Calculate the frequency of the light to three significant figures.