Question

--Given Values--
Atomic Radius (nm) = 0.116
FCC Metal = Gold
BCC Metal: = Sodium
Temperature ( C ) = 1017
Metal A = Tin
Equilibrium Number of Vacancies (m^-3) = 6.02E+23
Temperature for Metal A = 369
Metal B = Gallium

I need help with 3, 4, 6, 7, 11, 12. Am I entering the notations incorrectly?

) If the atomic radius of a metal is the value shown above and it has the face-centered cubic crystal structure, calculate the volume of its unit cell in nm³? Write your answers in Engineering Notation.  
        Your Answer =Correct! Exact Answer= 35.3E-3 +/- 1.00E-03%
2) What is the atomic packing factor for the BCC crystal structure?  
        Your Answer = Correct!
3) Find the theoretical density for the FCC Element shown above in g/cm³. Write your answer to the ten thousandths place (0.0000):  
        Your Answer = Incorrect.
4) Calculate the atomic radius, in nm, of the BCC Metal above utilizing the density and the atomic weight provided by examination booklet - Write your answer with 4 significant figures:  
        Your Answer = Incorrect.
5) Calculate the fraction of atom sites that are vacant for copper (Cu) at the temperature provided above. Assume an energy for vacancy formation of 0.90 eV/atom:  
        Your Answer =Correct! Exact Answer= 3.05E-04 +/- 1.00E-05%
6) Repeat the calculation in question 5 at room temperature (25 C):  
        Your Answer = Incorrect.
7) Calculate the energy (in eV/atom) for vacancy formation for the Metal A and the equilibrium number of vacancies at the temperature provided above - Write your answer with 4 significant figures:  
        Your Answer = Incorrect.
8)Calculate the number of atoms per cubic meter in Metal B (units atoms/m³). Write your answer with 4 significant figures :
        Your Answer =Correct! Exact Answer= 5.0961E+28 +/- 1.00E+26%
9) What is the composition, in atom percent, of an alloy that contains a) 36 g Metal A and b) 47 g Metal B? Composition for Metal A (%):  
        Your Answer =Correct! Exact Answer= 31.02769217 +/- 1.00E-01%
10) What is the composition, in atom percent, of an alloy that contains a) 36 g Metal A and b) 47 g Metal B? Composition for Metal B (%):  
        Your Answer =Correct! Exact Answer= 68.97230783 +/- 1.00E-01%
11) What is the composition of Metal A in atom percent, if the alloy consists of 4.5 wt% Metal A and 95.5 wt% of Metal B?  
        Your Answer = Incorrect.
12) What is the composition of Metal B in atom percent, if the alloy consists of 4.5 wt% Metal A and 95.5 wt% of Metal B?  
        Your Answer =

Answer 1