[" 2.How many unit cells are present in a cube-shaped ideal "],[" crystal of NaCl of mass "100g" ? [Atomic masses "Na=],[" 23."Cl=35.5]],[" (A) "1.28times10^(21)" unit cells "],[" (B) "1.71times10^(31)" unit cells "],[" (C) "2.57times10^(21)" unit cells "],[" (D) "5.14times10^(34)" unit cells "]