Barium has a work function of 2.48 eV. What is the maximum
kinetic energy of electrons...
Barium has a work function of 2.48 eV. What is the maximum
kinetic energy of electrons if the metal is illuminated by UV light
of wavelength 420 nm?
eV
What is their speed?
m/s
In an experiment electrons are released with a kinetic energy of
2.8 eV. The amazing physicists doing the experiments are increasing
the wavelength by 50%. Do you remember what happens? Are the
photoelectrons faster or slower? The energy now is 0.44 eV.
A) Based on that information, what is the material of the
cathode? (calculate the work function and compare to table 28.1 in
our textbook).
B) What is the initial wavelength of the light?
C) When you go a...
The maximum kinetic energy of photoelectrons is 2.80 eV . When
the wavelength of the light is increased by 50%, the maximum energy
decreases to 1.30 eV . What is the work function of the cathode?
What is the initial wavelength?
Electrons in an electron microscope have a kinetic energy of
1.20 105 eV. (a) Find the de Broglie wavelength of the electrons.
Incorrect: Your answer is incorrect. (b) Find the ratio of this
wavelength to the wavelength of light at the middle of the visible
spectrum (550 nm). (c) How many times greater magnification is
theoretically possible with this microscope than with a light
microscope?
Photons, electrons and atoms:
The work function ( ) of electrons in
sodium is 2.28 eV.
b. What total momentum
?(?,)
(formula) is transferred to the metal surface when a photon is
incident vertically and the photoelectron is emitted in the
opposite direction?
c. Assume that a (resting) free electron could
completely absorb a photon. What wavelength would the photon have
to have in order for the momentum balance to be fulfilled in this
case as well? Use the so-called...
A proton with initial kinetic energy 50.0 eV encounters a
barrier of height 70.0 eV. What is the width of the barrier if the
probability of tunneling is How does this compare with the barrier
width for an electron with the same energy tunneling through a
barrier of the same height with the same probability ?
a) An electron with 10.0 eV kinetic energy hits a 10.1 eV
potential energy barrier. Calculate the penetration depth.
b) A 10.0 eV proton encountering a 10.1 eV potential energy
barrier has a much smaller penetration depth than the value
calculated in (a). Why?
c) Give the classical penetration depth for a 10.0 eV particle
hitting a 10.1 eV barrier.
Cesium has a binding energy (“work function”) of 1.8 eV. When
cesium is illuminated with a light of a certain wavelength, the
electrons ejected from the surface have a kinetic energy of 2.2 eV.
What is the wavelength (nm) of the light?
a.A free (i.e. unbound) electron has a kinetic energy of 7.5 eV.
What is the angular wavenumber of the travelling wave that
describes the solution to Schr ̈odinger’s equation for this
particle?
b.A particle of mass 6.64 × 10-27 kg is confined in
an infinite square well of width 2.50 × 10-11 m. It is
observed to have an energy of 3.00 eV. How many nodes does its
wavefunction have? (Not including those at the walls of the
well.)
c.What...
Each of the electrons in the beam of a television tube has a
kinetic energy of 11.0 keV. The tube is oriented so that
the electrons move horizontally from geomagnetic south to
geomagnetic north. The vertical component of Earth's magnetic field
points down and has a magnitude of 50.0 μT.
1.What is the acceleration of a single electron due to the magnetic
field?
2.How far will the beam deflect in moving 20 cm through
the television tube?