I want to know which formula I have to use to solve this. Also please let me know the process of the calculate.

I want to know which formula I have to use to solve this. Also please let me know the process of the calculate. Find the concentration of phosphoroun (P) atoms in the meit to obtain Si doped with 104atom/cm2 (Czochinalshi growth) ky=0.35 for P in Si. 14=1c1=c4=0.3510afomui=2610 How many grams of P should be added if the initial load in the crucible is 5kg of 5s idersity of 5i=2.3ggg/cm3 )