Introduction of Atoms

The energy of an atom (or ion) in its ground state is −54.4 eV. It may be

We have stimulated emission and spontaneous emission. Do we also have stimulated absorption and spontaneous absorption?

What is the electric potential needed to excite He⁺ to its first excited state?

A hot gas emits radiation of wavelengths 46.0 nm, 82.8 nm and 103.5 nm only. Assume that the atoms have only two excited states and the difference between consecutive energy levels decreases as energy is increased. Taking the energy of the highest energy state to be zero, find the energies of the ground state and the first excited state.

The wavelength of the K_α line is ______ Pm in copper (Z = 29) if the wavelength of the K_α = line in iron (Z = 26) is known to be equal to 193 picometers.

An atom is in its excited state. Does the probability of its coming to ground state depend on whether the radiation is already present or not? If yes, does it also depend on the wavelength of the radiation present?

Three photons coming from excited atomic-hydrogen sample are picked up. Their energies are 12.1 eV, 10.2 eV and 1.9 eV. These photons must come from

How many wavelengths are emitted by atomic hydrogen in visible range (380 nm − 780 nm)? In the range 50 nm to 100 nm?