Photoelectron Spectroscopy

Question

I'm really stuck on this one.  I do not know where to begin and I am struggling with chemistry so if you could get me on track or help me figure out how solve this problem I would be very grateful.

 

One way to measure the ionization energy of atoms is to shine light with a specific wavelength at gas phase atoms, causing the outermost electrons to be ejected.  The kinetic energy (T) of these electrons can be found by measuring the velocity of the ejected electrons.  If Ep is the energy of the incident light, then by the conservation of energy Ep = Ei1 + T.  What is the ionization energy of rubidium (in kJ mol-1) if an incident light of 58.4 nm produces electrons with a velocity of 2.450x10^6 ms-1?

Answer 1

The energy of the photon is given by E_p = hc/λ and the kinetic energy of the electron is given by T = ½m_ev².

 

Use hc = 1.98644521 x 10^-25 J·m and m_e = 9.10938291 x 10^-31 kg for the constants in the problem.

 

You will solve E_i1 for a single event, so multiply the answer by Avogadro's number and divide by 1000 to get the units that you want: kJ/mole.

 

Good luck!