Cesium (Cs)

Practice

Practice cesium

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

1. Question 1Photoelectric effect: kinetic energy of ejected electronsExam level

   Light of wavelength $355\ \mathrm{nm}$ shines on a clean cesium surface. The work function of cesium is $\phi = 2.14\ \mathrm{eV}$ ($1\ \mathrm{eV} = 1.602 \times 10^{-19}\ \mathrm{J}$). What is the maximum kinetic energy of the ejected electrons, in J?

   Your answer (in the unit shown)

   $\mathrm{J}$

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

   CheckDifferent question

2. Question 2Photoelectric threshold and work functionExam level

   The work function of cesium is $\phi = 2.14\ \mathrm{eV}$ ($1\ \mathrm{eV} = 1.602 \times 10^{-19}\ \mathrm{J}$). What is the longest wavelength of light, in nm, that can eject electrons from cesium?

   Your answer (in the unit shown)

   $\mathrm{nm}$

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

   CheckDifferent question

3. Question 3Will these photons eject electrons?Exam level

   The work function of cesium is $\phi = 2.14\ \mathrm{eV}$ ($1\ \mathrm{eV} = 1.602 \times 10^{-19}\ \mathrm{J}$). Which of these wavelengths of light will eject electrons from cesium? Select all that apply.

   A$475\ \mathrm{nm}$B$720\ \mathrm{nm}$C$755\ \mathrm{nm}$D$645\ \mathrm{nm}$E$245\ \mathrm{nm}$

   CheckDifferent question