Q39) An unknown metal has an atomic mass of 184g/mol and the density of 19.3g/cm3 as crystals with the Body-Centered Cubic unit cells. Determine the radius of this metal atom (r) in pm unit: "Note: (a) Avogadro constant (N)=6.021023 (number of particles in one mole); (b) for a body-centered cubic unit cell, cell edge length 2.31r. A) 126 B) 137 C) 147 D) 158