Molybdenum metal must absorb radiation with an energy higher than 7.22 * 10-19 J ('energy threshold') before it can eject an electron from its surface via the photoelectric effect. (a) What is the frequency threshold for emission of electrons?

Video transcript

hey everyone in this example, we need to calculate the frequency threshold for the emission of electrons in iron. If the energy threshold via the photo electric effect is equivalent to this value given. So we're going to recall our formula for the energy of a photon, which we would recall is equal to Plank's constant, multiplied by our frequency. So because the prompt is asking for frequency, we're going to find frequency by isolating it from plank's constant so that we now have energy of our photon divided by Plank's constant. So to find frequency, we would say that it's equal to murder our energy threshold given in the prompt is 6.878 times 10 to the negative 19th power jewels. And in our denominator we would recall that Plank's constant is 6. times 10 to the negative 34th power units of jewels, times seconds. We're going to be able to cancel out jewels leaving us with inverse seconds as our final unit for frequency which is the proper unit. And we're going to get that our frequency is equal to a value of 1.03, 8 Times 10 to the 15th power inverse seconds. And so this will be our final answer. To complete this example as the frequency threshold for the emission of our electrons in our atoms of iron. If you have any questions, please leave them down below. Otherwise, I'll see everyone in the next practice video