Mark: A1:Cubic&Hexagonal Crystal Structures (Chapter 1) 7.5points a)What is the difference between octahedral gap in fcc and bcc with respect to size and shape? b) On which lattice voids are the C-atoms located in the bcc Fe-lattice?The following ratios of radii r/R between octahedral and tetrahedral void and the atom in the bcc- lattice are given(r-radius of void,R-radius of lattice atom). =0.29 Roctahedron =016，R.mm Explain your answer.Mark: A1: Cubic& Hexagonal Crystal Structures (Chapter 1) 7.5points a) What is the difference between octahedral gap in fcc and bcc with respect to size and shape? b) On which lattice voids are the C-atoms located in the bcc Fe-lattice? The following ratios of radii r / R between octahedral and tetrahedral void and the atom in the bcc￾lattice are given (r – radius of void, R – radius of lattice atom). Octahedron r 0.16 R = , tetrahedron r 0.29 R = Explain your answer