Ga ( atomic mass 70μ ) crystallizes in a hexagonal close packed structure. The total number of voids in 0.581 g of Ga is___ ×1021 .(Round off to the Nearest Integer)

Ga Crystallizes as H.C.PIf number of Particles per unit cell = n ,  number. of Tetrahedron voids = 2n number. of octahedron voids =   n,     Total = 3nno. of Ga particles given WGAW×NA=0.58170×6.023×1023=0.0499×1023 atom=0.58170×6.023×1023=0.0499×1023 atomFor one particles – 3 voids ∴  0.0499×1023→  ?0.0499×10231×3=0.1499×1023 voids∴ 14.99×1021≅15×1021  voids∴   X=15