What is the shortest wavelength present in the Paschen series of spectral lines?
1. \(818.9~\text{nm}\)
2. \(779~\text{nm}\)
3. \(500~\text{nm}\)
4. \(1024~\text{nm}\)

A difference of \(2.3\) eV separates two energy levels in an atom. What is the frequency of radiation emitted when the atom makes a transition from the upper level to the lower level?

The ground state energy of the hydrogen atom is –13.6 eV. What is the potential energy of the electron in this state?

1. -13.6 eV
2. 27.2 eV
3. -27.2 eV
4. 13.6 eV

The radius of the innermost electron orbit of a hydrogen atom is \(5.3\times10^{-11}\) m. $\mathrm{}$What is the radius of the \(n=2\) orbit?
1. \(1.67 ~\mathring A\)
2. \(4.77~\mathring A\)
3. \(2.12~\mathring A\)
4. \(3.11~\mathring A\)

A hydrogen atom initially in the ground level absorbs a photon, which excites it to the \(n=4\) level. The wavelength of the photon is:
1. \(97\) nm
2. \(99\) nm
3. \(95\) nm
4. \(96\) nm

The speed of the electron in a hydrogen atom in the \(\mathrm{n=1}\) level is:
1. \(1.1 \times10^{6} \) m/s
2. \(2.18 \times10^{6} \) m/s
3. \(1.08\times10^{6} \) m/s
4. \(3.07 \times10^{6} \) m/s

In accordance with Bohr’s model, what is the quantum number that characterizes the earth’s revolution around the sun in an orbit of radius $1.5\times {10}^{11} m$  with orbital speed $3\times {10}^4 m/s$? (Mass of earth = $6.0\times {10}^{24} kg.$)

1.  \(1.8\times 10^{76}\)
2. \(2.3 \times10^{74} \)
3. \(1.3 \times10^{76} \)
4. \(2.6 \times10^{74} \)

The total energy of an electron in the first excited state of the hydrogen atom is about \(-3.4\) eV. What is the kinetic energy of the electron in this state?
1. \(3.4\) eV
2. \(-3.4\) eV
3. \(3.2\) eV
4. \(-3.2\) eV

The total energy of an electron in the first excited state of the hydrogen atom is about -3.4 eV. What is the potential energy of the electron in this state?

1. 6.8 eV
2. -6.8 eV
3. 0
4. 3.4 eV

The ground state energy of a muonic hydrogen atom is:

(Mass of a negatively charged muon, $m_{\mu }=207 m_e$)

1. -2.07 keV
2. 2.81 keV
3. -2.81 keV
4. 2.07 keV