5. A sample of metallic Nickel has a mass of 5.0 grams. a) How many atoms are present? b) How many atoms are in each unit cell (show how you derived the answer)? c) How many unit cells are present in 5.0 grams? d) If the density of Ni is 8.90grams/cm3, what is the volume of a unit cell? e) Determine the "a" dimension of the unit cell ( a= length of the unit cell from the answer calculated above in " d