A minimum energy of 7.21 * 10-19 J is required to produce the pho...

Question

A minimum energy of 7.21 * 10-19 J is required to produce the photoelectric effect in chromium metal. 
(a) What is the minimum frequency of light needed to remove an electron from chromium?

Accepted Answer

Hello everyone today. We have the following problem. If at least 3.94 times 10 to the negative 18 jewels of energy is required to induce the photo electric effect. What is the lowest light frequency required to eject an electron from a pure metal sample? So from this, it's important to recall at a very important equation known as Plank's equation. And Plank's equation says that the energy of a photon is equal to Planck's constant times the frequency. And so essentially we want to solve for the frequency. So we have to rearrange this equation so that we get the frequency is equal to the energy of the photon over Plank's constant. And so we simply have to plug in our values to solve our frequency. So the energy of the photon is 3.94 times 10 to the negative 18th jewels And Planck's constant is going to be 6.6-6 Times 10 to the negative 34 jules, times seconds. When our units of jewels cancel out, we will be left with a frequency of 5.95 times to the 15th seconds to the negative first power since seconds was in the denominator in the equation. And so this is going to be the lowest frequency required to eject an electron from a pure metal sample overall, I hope that this helped. And until next time

Watch next