1. The problem statement, all variables and given/known data Estimate the electrical conductivity, at 135°C, of silicon that has been doped with 3 x 1024 per meter cubed of aluminum atoms. Assume values for electron and hole mobilities of 0.03 and 0.007 m2/V-s, respectively. 2. Relevant equations σ=|e|(ne*μe+nh*μh) σ=conductivity e=1.6*10-19 ne=number of free electrons μe=electron mobility nh=number of holes μh=hole mobility 3. The attempt at a solution So far I have this: σ=1.6*10-19*(ne*0.03+3*1024*0.007) I don't know how to find ne. Is it the same value of nh?