The number of
electrons ejected can be determined by measuring the current between the wire and plate
. The more light, the more electrons; a little circuitry allows this device to be used as a light meter. What is really important about the photoelectric effect
What causes an electron to be ejected?
In the photoelectric effect
What is electron ejection?
When light shines on a metal, electrons can be ejected from the surface of the metal in a phenomenon known as the
photoelectric effect
What are the condition for ejection of electron from the surface of metal?
Re: Conditions that allow electron to be ejected from metal surface. Energy of the
photon must be greater than or equal to the energy of an electron
.
Why E PC is not valid for electron?
The equation E = pc is valid for a particle with
zero rest mass
. The rest mass of a photon is zero, but the rest mass of an electron is not zero. So, the equation will be valid for photon, and not electron.
What is the minimum energy required to remove an electron?
Ionization energy (IE)
is the minimum energy required to remove an electron from the nth state of a gaseous atom, molecule or ion.
Will an electron be ejected from the metal?
When light shines on a metal, electrons can be ejected from the surface of the metal in a phenomenon known as
the photoelectric effect
What is the minimum frequency light must have to eject an electron from the surface?
The minimum energy required to eject an electron from the surface is called the photoelectric work function. The threshold for this element corresponds to a wavelength
of 683 nm
. Using this wavelength in the Planck relationship gives a photon energy of 1.82 eV.
What is the best description of threshold frequency?
What is the best description of ‘threshold frequency
‘? The minimum energy needed for electrons to escape a surface.
Is E mc2 valid for electron?
You can use E=mc
2
for the hamburger you’re eating, for a photon
or for an electron
. But in the case of a photon the mass is its momentum (this means that a rest mass doesn’t exist for a photon since a stationary photon doesn’t exist!), in fact you have: E = mc
2
=> m = E / c
2
= hc / λ = photon’s momentum.
Is it always possible to see photoelectric effect with red light?
Explanation: Because light behaves like particles rather than a continuous stream, even very
high -intensity red light will never be able to
overcome an electrons’ work function (in this situation), as every individual photon fails to do so. …
What will happen to photoelectric effect when intensity is increased?
Increasing the light intensity (photon energy per second per unit area)
increases the rate at which electrons leave the metal, and the electrons have more kinetic energy
. Changing the frequency of the light while keeping the intensity constant should not change the rate of electron emission.
What is the minimum energy needed to remove an electron from silver?
Transcribed image text: The minimum energy needed to remove an electron from the surface of a silver coating is
6.88 x 10-19 J.
What is the ability to attract electrons?
Electronegativity
is a property that describes the tendency of an atom to attract electrons (or electron density) toward itself. An atom’s electronegativity is affected by both its atomic number and the size of the atom. The higher its electronegativity, the more an element attracts electrons.
Is light a wave or a particle?
Einstein believed light is a particle (photon) and the flow of photons is a wave. The main point of Einstein’s light quantum theory is that light’s energy is related to its oscillation frequency.
