## Calculate the Ionization energy... midterm Q3B

Hannah Morales 1D
Posts: 31
Joined: Fri Sep 29, 2017 7:06 am

### Calculate the Ionization energy... midterm Q3B

Calculate the ionization energy or a rubidium atom, given that radiation of a wavelength 58.4 no produces electrons with a speed of 2450 km*s^-1, recall that 1J= 1kg*m^2*s^-2

So I am a bit confused on this question because what I did was that
Frequency= c(speed of light)/wavelength( 58.4*10^-9m)
Then I used the formula E= planks constant * frequency (5.14*10^15)
And I thought what I would get from here is the work function. I know the solution is on the class website but I was wondering if anyone can help explain to me what I have to do next time.

Andre_Galenchik_2L
Posts: 69
Joined: Fri Sep 28, 2018 12:23 am

### Re: Calculate the Ionization energy... midterm Q3B

You need to use the conversation of energy equation expressed during the photoelectric effect: Energy of photon = Work Function + Kinetic Energy of released electron. You were able to find the energy of the photon correctly, you just forgot to find the KE of the electron through using the equation KE =1/2 mv^2. After you find KE, just find the work function (which is the ionization energy) through the conservation of energy equation.