An atom with one electron has an ionization energy of $25\ \mathrm{eV}$. How much energy will be released when the electron makes the transition from an excited energy level, where $E=-16\ \mathrm{eV}$, to the ground state?
A) $9\ \mathrm{eV}$
B) $11\ \mathrm{eV}$
C) $16\ \mathrm{eV}$
D) $25\ \mathrm{eV}$
E) $41\ \mathrm{eV}$
A) $9\ \mathrm{eV}$
B) $11\ \mathrm{eV}$
C) $16\ \mathrm{eV}$
D) $25\ \mathrm{eV}$
E) $41\ \mathrm{eV}$
If the atom’s ionization energy is $25\ \mathrm{eV}$, then the electron’s ground‑state energy must be $-25\ \mathrm{eV}$. Making a transition from the $-16\ \mathrm{eV}$ energy level to the ground state will cause the emission of a photon of energy
$$\Delta E=(-16\ \mathrm{eV})-(-25\ \mathrm{eV})$$
$$\Delta E=9\ \mathrm{eV}$$