The coordination number of a body centered atom in cubic structure is 8.
A body centered cubic (bcc) structure is a type of crystal structure in which each atom is surrounded by eight other atoms. The atoms are arranged in a cubic lattice, with one atom at the center of each cube and one atom at each corner of the cube. The coordination number of an atom is the number of atoms that are directly bonded to it. In a bcc structure, each atom is bonded to eight other atoms, so the coordination number is 8.
The other options are incorrect because they do not represent the number of atoms that are directly bonded to an atom in a bcc structure. Option A, 4, is the coordination number of an atom in a face-centered cubic (fcc) structure. Option B, 6, is the coordination number of an atom in a hexagonal close-packed (hcp) structure. Option C, 10, is the coordination number of an atom in a body-centered tetragonal (bct) structure.