At (T( ~K ) ), copper (atomic mass (=635 u ) ) has fcc unit cell structure with edge length of (x Å ). What is the approximate density of ( Cu ) in ( g cm ⁻³ ) at that temperature? ( (N_A=6.0 10²³ ~mol ⁻¹ ) )

Step-by-step solution

Given, fcc unit cell is present, (Z=4 ) Edge length (=x Å ) Atomic weight (=63.5 ~g ~mol ⁻¹ ) ( Density, d= Z atomic weight a^3 N_A ) where, ( a= ) edge length ( aligned d & = Z atomic weight x^3 6.023 10²³ (10⁻⁸ )^3 & = 4 63.5 x^3 6.023 10²³ 10⁻²⁴ d & = 423.0 x^3 aligned ) Hence, option (3) is correct.