The energy required to ionize sodium is 496 kJ/mol. What minimum frequency of light is required to ionize sodium?

Video transcript

hey everyone in this example we need to calculate the frequency in hertz needed to ionized potassium given its ionization energy in joules per mole. So our first step is to recall our formula for the calculation of frequency. And we should recall that that is equal to energy divided by plank's constant. Now we should recall that also our units for Planck's constant is equal to jewels time seconds. And because our final answer should be in hurts, we want to recall that The units for Hertz is equivalent to one over seconds. Or we can say that hurts. Time seconds is equal 21. So now that we have this info outlined, let's go ahead and get into our formula. So we should have that our frequency is equal to energy and our numerator. So let's start with writing out our numerator. So what we should have for our Energy is we're going to plug in that ionization energy info so we should have 43, jewels per mole. And our next step is to make sure that we include a conversion factor so that our final answer isn't hurts. So we're going to actually multiply this quantity by our conversion factor for hertz. So again we said that 1 2nd times hurts or hurts. Time seconds is equal to one. So we're just going to place this over one. So that this essentially means hurts time seconds. Next we want to make sure we can get rid of the mole in the denominator of our numerator. So we're going to multiply by our conversion factor. That we should recall where one mole Is equal to 6.022 times 10 to the 23rd power atoms. And this is what we know as avocados number. Now in our denominator we have to plug in Plank's constant. So we should recall that. That's 6.626 times 10 to the negative 34th power jules times seconds. And so now that we have everything plugged into our formula, we can focus on how the units will cancel out. So we'll be able to actually get rid of the jewel term as well as canceling out our mole term. And then lastly we can go ahead and get rid of the seconds. And so that leaves us with just hurts alone which is exactly what we want. So we can go ahead and calculate in our calculators and what we should get for our final result is 1.09 times 10 to the 14th power hurts as our final answer. And this is going to be our frequency that we need to lionize our potassium atom by knocking the electrons out of the valence shell of our potassium. So one point oh nine times 10 to the 14 hertz is our final answer. I hope that everything we reviewed was clear. But if you have any questions, please leave them down below and I will see everyone in the next practice video