Home
Class 11
CHEMISTRY
Energy required to stop the ejection of ...

Energy required to stop the ejection of electrons from Cu-plate 0.27 eV. Calculate the work function (in eV) When radiation of `lambda`= 235nm strikes the plate.

Text Solution

Verified by Experts

The correct Answer is:
5
`E_("photon") =` Work function +`1/2 mv^2`
=work function +`underset("Stopping potential")underset(to)(eV_0)" ` ….(i)
`E_("Photon") = (hc)/(lambda) = (6.625xx10^(-34) xx 3xx10^8)/(235 xx 10^(-9)) = 5.27 eV`
from equation (i) `E_("photon") = W_0 + 0.27`
`implies W_0 = E_("Photon") - 0.27 = 5eV`
Promotional Banner

Similar Questions

Explore conceptually related problems

The minimum energy required for the photo emission of electrons from the surface of a metal is 4.95xx10^(-19)J . Calculate the critical frequency and the corresponding wave length of the photon required to eject the electron.

When a metal surface is exposed to certain frequency of electromagnetic radiation. The kinetic energy of electron ejected from metal surface is 0.20 eV. If its work function (W_(0)) is 4.80 eV, the approximate frequency of radiation falling on the metal surface in Hz is

Photon having energy equivalent to the binding energy of 4^(th) state of He^+ atom is used to eject an electron from the metal surface of work function 1.4 eV. If electrons are further accelerated through the potential difference of 4V then the minimum value of De-broglie wavelength associated with the electron is :

Light of intensity 10^(-5) W m^(-2) falls on a sodium photo-cell of surface area 2 cm^(2) . Assuming that the top 5 layers of sodium absorb the incident energy, estimate time required for photoelectric emission in the wave-picture of radiation. The work function for the metal is given to be about 2 eV. What is the implication of your answer?

Radiations of two different frequencies whose photon energies are 3.4 eV and 8.2 eV successively illuminate a metal surface whose work function is 1.8eV. The ratio of the maximum speeds of the emitted electrons will be

In photoelectric effect, if the energy required to overcome the attractive forces on the electron (work functions) of Li, Na and Rb are 2.41 eV, 2.30 eV and 2.09 eV respectively, the work function of ‘K’ could approximately be in eV

Light of wavelength 488 nm is produced by an argon laser which is used in the photoelectric effect. When light from this spectral line is incident on the emitter, the stopping (cut - off) potential of photoelectrons is 0.38 V. Find the work function of the material from which the emitter is made.

When light of frequency nu incidents on two metallic plates A and B photo electrons are emitted . If the work function of A is more than that of B the correct curve of the following curves drawn between stopping potential V and incident frequency nu is

The surface of a metal is illuminated with the ight of 400nm. The kinetic energy of the ejected photoelectrons was found to be 1.68 eV. The work function of the metal is: (hc=1240 eV. nm)