Photodissociation of water

$$\mathrm{H}_2 \mathrm{O}(l)+h v \longrightarrow \mathrm{H}_2(g)+\frac{1}{2} \mathrm{O}_2(g)$$

has been suggested as a source of hydrogen. The energy for the reaction is $285.8 \mathrm{~kJ}$ per mole of water decomposed. Calculate the maximum wavelength (in $\mathrm{nm}$ ) that would provide the necessary energy. In principle, is it feasible to use sunlight as a source of energy for this process?

When a compound containing cesium ion is heated in a Bunsen burner flame, photons of energy of $4.30 \times 10^{19} \ J$ are emitted. What color is a cesium flame?

The radioactive Co-60 isotope is used in nuclear medicine to treat certain types of cancer. Calculate the wavelength and frequency of emitted gamma radiation photons having energy equal to $1.29 \times 10^{11} \ J\ mol^1$.

An electron in a hydrogen atom is excited from the ground state to the n = 4 states. Which of the following statements are true and which are false?
The wavelength of light the atom absorbs in going from n 5 1 to n 5 4 is the same as that emitted as it goes from n = 4 to n = 1.

An electron in a hydrogen atom is excited from the ground state to the n = 4 state. The wavelength of light emitted when the electron drops from n = 4 to n = 1 is longer than that from n = 4 to n = 2, statement is true and which are false?

An electron in a hydrogen atom is excited from the ground state to the n = 4 states. Which of the following statements are true and which are false?
The electron is farther from the nucleus (on average) in n = 4 than in the ground state.

An electron in a hydrogen atom is excited from the ground state to the n = 4 states. Which of the following statements are true and which are false?
It takes more energy to ionize (remove) the electron from n = 4 than from the ground state.

An electron in a hydrogen atom is excited from the ground state to the n = 4 states. Which of the following statements are true and which are false?
The n = 4 state is the first excited state.

A photon has a wavelength of 624 nm. Calculate the energy of the photon in joules.

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 $n_1$?

The ionization energy is the energy required to completely remove an electron from the ground state of an atom or ion. Calculate the ionization energies (in KJ $mol^{-1} )$ of the $He^+$ and $Li^{2+}$ ions.

What are the similarities and differences between a $2 p_{x}$ and a $3 p_{y}$ hydrogen like orbital?

Discuss the similarities and differences between a 1 s and a 2 s hydrogen like orbital.

Calculate the total number of electrons that can occupy
seven f orbitals.