How many lithium atoms are present in a unit cell with edge length 3.5 Å and density 0.53 gcm –3? (Atomic mass of Li = 6.94)

Let the no. of atoms in a unit cell be Z Then density 3 . A Z M N a x 3 23 8 23 24 1 6.94 0.53 6.023 10 3.5 10 6.94 0.53 6.023 42.875 10 6.94 13.6865 136.864 2 6.94 10 x x x x x x x x >> Z Z Z Z