Silver forms ccp lattice and X-ray studies of its crystals show that the edge length of its unit cell is 408.6 pm. Calculate the density of silver
(Atomic mass = 107.9 u).

Explanation

Since the lattice is ccp, the number of silver atoms per unit cell `= z = 4`
`"Molar mass of silver "= 107.9" g mol"^(-1) = 107.9×10^(-3)" kg mol"^(-1)`
`"Edge length of unit cell "= a = "408.6 pm" = 408.6xx10^(-12) m`
Density, `a=(s.M)/(a^(3).N_(A))`
`=(4xx(107.9xx10^(-3)" kg mol"^(-1)))/((408.6xx10^(-12)m)^(3)(6.022xx10^(23)" mol"^(-1)))=10.5xx10^(3)kg m^(-3)`
`=10.5gcm^(-3)`