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Photoelectric effect: Threshold frequency

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Wize University Chemistry Textbook > Early Atomic Theory to Quantum Theory

The Photoelectric Effect

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If we are told that a certain metal's threshold frequency to displace an electron is 9.12x1014Hz and we shine violet light (400nm) on the metal, would an electron be displaced?


Let's first write out our light equations so we can be reminded of how the variables are related:
E=hv c=λ(v)

Are the variables directly or indirectly proportional?

As frequency increases what happens to energy?

As wavelength increases what happens to frequency?

As wavelength increases what happens to energy?


Ok back to this question!

Is the threshold frequency a minimum or maximum frequency value?
Minimum
If that's the case then would the threshold frequency correspond to the minimum or maximum wavelength?
Maximum

Let's calculate the wavelength of the photon with the frequency provided:



How many nm does this wavelength correspond to?


Therefore, would the violet light (400nm) be able to displace an electron?


More The Photoelectric Effect Questions:
If a photon was able to remove an electron from a metal plate that had a binding energy of 2 x 10-20 J, what was the frequency of the wave?
If the answer has an exponent write it like this 1.23x10^4 (no spaces)
Work Function
The work function of metallic cesium is 3.36×10−19 J. What is the threshold wavelength of light required to emit electrons from the surface of metallic cesium?
Photoelectric Effect
The threshold wavelength for a neodymium (Nd) metal surface is 387 nm. What wavelength of light causes electrons to be ejected from the surface with a maximum kinetic energy of 1.473×10−18 J? (Choose the closest answer.)
Work Function
X-ray of frequency 1.53 ⋅\cdot 1016 Hz cause emission of electrons from a metal surface with a maximum kinetic energy of 1.313 ⋅\cdot 106 Jmol−1. Calculate the threshold frequency of the material.
An element is bombarded with a beam of X-rays of wavelength 0.75664 nm. Upon irradiation electrons are ejected with a velocity of 2.35 x 107 m/s.
Photoelectric effect: Work Function of Platinum
The binding energy for a material, sometimes know as the work function, can be found by irradiating a surface with a laser of sufficiently high energy and then measuring the kinetic energy of the ejected electrons. A researcher has found a new morphology of Platinum and is wondering if the work function has been modified. To test this the researcher irradiates the new form of Platinum with a UV-Laser with a wavelength of 125 nm and measures the kinetic energy of the electrons being ejected at 5.74 x 10-19 J. What is the work function of the new Platinum morphology? (1.60 x 10-19J = 1 eV)
Photoelectric effect: Binding Energy of Platinum
The binding energy for a material, sometimes known as the work function, can be found by irradiating a surface with a laser of sufficiently high energy and then measuring the kinetic energy of the ejected electrons. A researcher has found a new morphology of Platinum and is wondering if the binding energy has been modified. To test this the researcher irradiates the new form of Platinum with a UV-Laser with a wavelength of 125 nm and measures the kinetic energy of the electrons being ejected at 5.74 x 10-19 J. What is the binding energy of the new Platinum morphology? (1.60 x 10-19J = 1 eV)
The binding energy of Fe(s) is 612 kJ/mol.
a) What is the longest wavelength of light that can ionize a sample of iron metal? (Report your answer to three significant figures in nm; do not include the unit in the answer field)
b) Iron is irradiated with light of wavelength 12nm. What velocity does the electron leave the surface with? (Report your to three significant figures in scientific notation in m/s; do not include the unit in the answer field)
Periodic Trends: Ionization of an Excited Hydrogen Atom
A sample of hydrogen atoms is thermally excited so that the electrons are resting in the n=3 state. What is the wavelength of the lowest energy photon capable of ionizing these excited hydrogen atoms?
Elements: Binding Energy
An element is bombarded with a beam of X-rays of wavelength 0.75664nm. Upon irradiation, electrons are ejected with a velocity of 2.35 x 107 m/s.
What is the binding energy for the element?
Photoelectric effect: Practice
A metal surface is irradiated by light from a laser with a wavelength of 492 nm. No electrons are measured leaving the surface. What is the most likely explanation