1. Determine the concentration of vacancies (Nv/N) in Cu at 27 C (300 K) and one degree celcius below the melting point, 1083C (1356 K). The activation energy of vacancy formation is -83,600 J/mole, and the gas constant R is 8.31 J/mol*K. 2. (1) Predict the kind of solid solution formed between (1) Fe in Cr, and (2) N in Fe? Provide step-by-step analysis using Hume-Rothery rules if it's substitutional. 3. A ductile iron has 3.50 weight percent of carbon and 2.50 weight percent of silicon and assume the rest is iron. Calculate the concentration of carbon and silicon in this ductile iron in terms of atomic percent. WILEX