1. The problem statement, all variables and given/known data The concentration of electrons per unit volume is given (atoms/m^3), temperature is also given in Kelvins (100 K). Other values were also given such as valence but I'm pretty sure that they are irrelevant. 2. Relevant equations λ = 1/ pi * d^2 * n λ=kT/4∗π∗√2∗r^2*p 3. The attempt at a solution n is given but I can't find other relevant values to be inserted in the equation since d is missing and the problem didn't provide it. On the second equation, pressure is missing but I don't know if I can assume that the pressure is 1 atm.