1. a) Knowing that the  number of intrinsic carriers for silicon at 300˚K is 1.5*10^10, what is the number of intrinsic carriers (ni) in silicon if its temperature is elevated to 600˚K? 

b) To achieve an N-type doping level of 1015cm-3 using phosphorous how many grams of pure phosphorous has to be added to every kilogram of pure silicon? (density of silicon is2328kg/m3, and its atomic mass is 28, atomic mass of phosphorous is 31) Hint: Atomic mass of Phosphorous is 31, which means that the mass of 6.02×10^23 atoms of phosphorous is 31 grams.

c) What is the concentration of n and p carriers for the resulting N-type silicon? Where is the Fermi level with respect to valence and conduction bands? 

d) Calculate the carrier concentrations of the same doped silicon at 600˚K. Can you still neglect the intrinsic carriers?