State the Bohr angular momentum quantization rule.

State the hydrogen Bohr energy formula.

What is the physical meaning of negative energy in the hydrogen Bohr model?

Find the energy of the \(n=2\) level in hydrogen.

Find the energy of the \(n=3\) level in hydrogen.

A hydrogen atom changes from \(n=3\) to \(n=2\). Find the photon energy.

Find the wavelength of the \(n=3\to n=2\) photon using \(hc=1240\,\mathrm{eV\,nm}\).

State how Bohr orbit radius depends on \(n\) for hydrogen.

Find the radius of the \(n=3\) Bohr orbit in terms of \(a_0\).

A hydrogen atom is ionized from the ground state. What minimum energy is required?

Find the ionization energy from the \(n=2\) hydrogen level.

A photon of energy \(10.2\,\mathrm{eV}\) is absorbed by ground-state hydrogen. Which level is reached?

Explain why a transition from \(n=2\) to \(n=3\) requires absorption rather than emission.

Find the energy and wavelength of a hydrogen photon emitted by \(n=4\to n=2\).

Why does the Bohr model work best for hydrogen-like atoms?

Derive Bohr angular momentum quantization from the electron standing-wave condition.

Show that larger \(n\) levels in hydrogen become closer together in energy.

Explain why Bohr's stationary states avoid the classical radiation problem.

A hydrogen atom emits a photon while ending in \(n=1\). Why is this photon more energetic than a comparable transition ending in \(n=2\)?

Connect the Bohr model to matter waves in one argument.