Lithium is used in a photoelectric effect experiment. If its work function is 2.95 eV, what frequency of light is the threshold frequency? Describe what happens to the electrons (in terms of energy and speed) if light with higher frequency strikes the lithium instead

Light of wavelength 350 nm falls on a potassium surface, and the photoelectrons have amaximum kinetic energy of 1.3 eV.What is the work function of potassium?The speed of light is 3 × 108 m/s and Planck’sconstant is 6.63 × 10−34 J · s.Answer in units of eV. What is the threshold frequency for potassium?Answer in units of Hz.

Calculate the de Broglie wavelength (in fm) of a 5.8 MeV a particle emitted from an atomic nucleus whose diameter is approximately 1.6 × 10¯14, fm Calculate its minimum kinetic energy (in keV) according to the uncertainty principle. keV Could this particle exist inside the nucleus? Yes No Explain. m.

A certain X-ray machine generates X-rays from a beam of electrons accelerated from zero to 99.9999999 per cent the speed of light in a long linear accelerator of length 3.2 km. The electrons are generated in pulses of duration ∆t = 100 fs. The generated x-rays from the target are also short pulses (λ = 0.15 nm). Determine the energy of a single x-ray photon in the beam. a.) 8.27 eV              b.) 8.27 J                           c.) 8.27 keV                     d.) none of these.

= 1. Photoelectric effect. In a photoelectric experiment in which monochromatic light of wave- length \ falls on a potassium surface, it is found that the stopping potential Vstop is 1.9 V for > 300 nm and 0.88 V for \ = 400 nm. Imagine we know neither Planck's constant, nor the workfunction for potassium, nor the threshold frequency fo. But assume we do know the elementary charge e 1.60 × 10-19 C and want to test the theoretical prediction of Eintsein's theory. = (a) From the given data, calculate a value for Planck's constant, h. (b) From the same data, find the workfunction Eo and the threshold frequency fo for potas- sium. (c) Then compare your results for h and Eo to their known values (see Knight, Table 38.1 for the work function). (d) Plot eVstop as a linear function of frequency f. Include the information you have found in parts (a) and (b) as well as the experimental data.

You set up a photoelectric experiment with an unknown metal to eject electrons. You use light of wavelength λ = 660 nm, which just BARELY ejects electrons from the metal. Planck s constant is either h = 6.63 x 10-34 J.s or h = 4.14 x 10-15 ev.s. a) What is the binding energy of the unknown metal in eV? eV b) You change the light source to one with a wavelength of λ = 300 nm. Using the binding energy you found in the previous step, find the maximum kinetic energy of an electron that is ejected from the metal in Joules. c) What is the stopping voltage for an electron with the kinetic energy you just found? Submit Answer