What does work function depend on?
What does work function depend on?
Work functions depend on the structure and chemical composition of a surface. For example, different crystallographic surfaces of the same metal or compound can have substantially different work functions. Chemical modifications of a surface can have even larger consequences.
How do you calculate threshold frequency?
Calculate the threshold frequency for a metal with a work function of 3eV. f = W/h where h is planck’s constant. Therefore if we know the work fucntion we can work out the threshold frequency but don’t forget to convert 3eV into J. 1eV = 1.6 x 10^{-19} J.
How do you find the threshold frequency on a graph?
So plotting a graph of frequency (f) on the x-axis and maximum kinetic energy (Ek) on the y-axis will give a straight line graph. Where the gradient is the Plank constant (h) and the y intercept is the work function(f), the intercept on the x-axis is the threshold frequency f0.
What is the difference between threshold frequency and work function?
The energy and frequency of a photon are related by: The minimum energy required to produce photo-emission of electrons is called the work function this depends on the type of metal used. The minimum frequency of light required to give the work function energy is called the threshold frequency.
What is the threshold frequency of sodium?
Sodium metal has a threshold frequency of 4.40×1014 Hz.
What is the symbol of threshold frequency?
electromagnetic phenomena The photoelectric threshold frequency, symbolized by the Greek letter nu with subscript zero, ν0, is that frequency at which the effect is barely possible; it is given by the ratio of the work function symbolized by the Greek letter psi, ψ, to Planck’s constant (ν0 =…
What is the threshold?
A threshold is what you step across when you enter a room. A threshold takes you from one place into another, and when you’re about to start something new, you’re also on a threshold. A threshold is a point of departure or transition.
What is minimum threshold frequency?
The threshold frequency is defined as a minimum frequency under which the photoelectric emission is not possible, regardless of the incident radiation intensity.
What is a threshold wavelength?
Thus threshold wavelength is the maximum wavelength that the incident radiation must have so that photoelectric effect takes place.
What is the formula of threshold energy?
Kmin = Kth = −Q MX + mx MX This equation is valid if the energies are much less than rest mass energies of the involved particles. In other words, the kinetic energy and momentum of particles can be treated classically, or non-relativistic.
What is the formula of threshold wavelength?
Given: Work function of platinum = Φ = 6.3 eV =6.3 x 1.6 x 10-19 J, Threshold wavelength of silver = 1972 Å = 1972 x 10-10 m, speed of light = c = 3 x 108 m/s, To Find: Planck’s constant = h =? Example – 10: The photoelectric work function of metal is 1.32 eV.
What is the threshold wavelength for the photoelectric effect?
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.
Who gives photoelectric effect?
The photoelectric effect was discovered in 1887 by the German physicist Heinrich Rudolf Hertz. In connection with work on radio waves, Hertz observed that, when ultraviolet light shines on two metal electrodes with a voltage applied across them, the light changes the voltage at which sparking takes place.
What are the laws of photoelectric effect?
When light is incident on the surface of the metal, the photons collide with the free electrons near the surface and transfer their energy into the electrons. If the energy is greater than a particular value, the electrons are ejected out of the metal. These ejected electrons are called photoelectrons.
What is photoelectric effect with Diagram?
The photoelectric effect is a phenomenon in physics. The effect is based on the idea that electromagnetic radiation is made of a series of particles called photons. When a photon hits an electron on a metal surface, the electron can be emitted. The emitted electrons are called photoelectrons.
What is the formula of photoelectric effect?
The Formula for Photoelectric Effect According to the famous Einstein explanation of the photoelectric effect: The energy of the photon will be sum total of energy needed to remove the electron and kinetic energy of the emitted electron. Thus h ν = W + E h \nu= W + E hν=W+E.
How did Einstein prove the photoelectric effect?
Light, Einstein said, is a beam of particles whose energies are related to their frequencies according to Planck’s formula. When that beam is directed at a metal, the photons collide with the atoms. If a photon’s frequency is sufficient to knock off an electron, the collision produces the photoelectric effect.
What is Einstein photoelectric equation?
: an equation in physics giving the kinetic energy of a photoelectron emitted from a metal as a result of the absorption of a radiation quantum: Ek=hν−ω where Ek is the kinetic energy of the photoelectron, h is the Planck constant, ν is the frequency associated with the radiation quantum, and ω the work function of the …
What is Einstein equation?
E = mc2, equation in German-born physicist Albert Einstein’s theory of special relativity that expresses the fact that mass and energy are the same physical entity and can be changed into each other.
What is photoelectric effect and define threshold frequency?
Threshold frequency: Threshold frequency is the minimum frequency of the incident radiation below which photoelectric emission is not possible irrespective of the intensity of the incident radiation. …
What is the value of one Einstein?
The einstein is a unit defined as the energy in one mole of photons (6.022×1023 photons). Because energy is inversely proportional to wavelength, the unit is frequency dependent. This unit is not part of the International System of Units and is redundant with the joule.