91Ó°ÊÓ

(a) A \(\gamma\) -ray photon has a momentum of \(8.00 \times 10^{-21} \mathrm{~kg} \cdot \mathrm{m} / \mathrm{s}\). What is its wavelength? (b) Calculate its energy in MeV

Find the longest-wavelength photon that can eject an electron from potassium, given that the binding energy is \(2.24 \mathrm{eV}\). Is this radiation?

Calculate the binding energy in eV of electrons in aluminum, if the longest- wavelength photon that can eject them is \(304 \mathrm{~nm}\).

What net charge would you place on a \(100 \mathrm{g}\) piece of sulfur if you put an extra electron on 1 in \(10^{12}\) of its atoms? (Sulfur has an atomic mass of 32.1.)

What is the maximum kinetic energy in eV of electrons ejected from sodium metal by 450 -nm EM radiation, given that the bindir \(2.28 \mathrm{eV} ?\)

Experiments are performed with ultracold neutrons having velocities as small as \(1.00 \mathrm{~m} / \mathrm{s}\). (a) What is the wavelength of such a neutron? (b) What is its kinetic energy in eV?

How many coulombs of positive charge are there in 4.00 kg of plutonium, given its atomic mass is 244 and that each plutonium atom has 94 protons?

What is the energy in joules and eV of a photon in a radio wave from an AM station that has a \(1530-\mathrm{kHz}\) broadcast frequency?

UV radiation having a wavelength of \(120 \mathrm{~nm}\) falls on gold metal, to which electrons are bound by \(4.82 \mathrm{eV}\). What is the maximum energy of the ejected photoelectrons?

(a) Find the energy in joules and eV of photons in radio waves from an FM station that has a 90.0-MHz broadcast frequency. (b) What does this imply about the number of photons per second that the radio station must broadcast?