Lithium (Li)

Practice

Practice lithium

Questions from the course about lithium. If you’re signed in, your answers count toward your progress.

1. Question 1Energy levels of hydrogen-like ionsExam level

   What is the energy of the electron in the $n = 1$ level of a $\ce{Li^2+}$ ion, in J? Include the sign. ($R_H = 2.179 \times 10^{-18}\ \mathrm{J}$)

   Your answer (in the unit shown)

   $\mathrm{J}$

   Scientific notation: type 4.86e-7 or 4.86 x 10^-7.

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2. Question 2Photoelectric effect: kinetic energy of ejected electronsExam level

   Light of wavelength $357\ \mathrm{nm}$ shines on a clean lithium surface. The work function of lithium is $\phi = 2.93\ \mathrm{eV}$ ($1\ \mathrm{eV} = 1.602 \times 10^{-19}\ \mathrm{J}$). What is the maximum kinetic energy of the ejected electrons, in eV?

   Your answer (in the unit shown)

   $\mathrm{eV}$

   Scientific notation: type 4.86e-7 or 4.86 x 10^-7.

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3. Question 3Ground-state electron configurationWarm-up

   Which is the ground-state electron configuration of a neutral lithium atom ($\ce{Li}$)?

   A$1s^{2}\,2s^{2}\,2p^{1}$B$1s^{2}\,2s^{2}$C$1s^{2}\,2s^{1}$D$1s^{2}$

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