Question

1) For a metal that has the face-centered cubic (FCC) crystal structure, calculate the atomic radius if the metal has a density of (8.000x10^0) g/cm³ and an atomic weight of (5.80x10^1) g/mol.  Express your answer in nm.

2) Consider a copper-aluminum solid solution containing (7.82x10^1) at% Al. How many atoms per cubic centimeter (atoms/cm^3) of copper are there in this solution? Take the density of copper to be 8.94 g/cm³ and the density of aluminum to be 2.71 g/cm³.

Answer 1

1)

Mass of 1 atom = 58 g/mol / (6.022 x 10²³ atoms mol¯¹ ) = 9.63 x 10^-23 g

Each FCC contains 4 atoms.

so, 4 x 9.63 x 10^-23 g / unit cell

volume = mass/density = 4 x 9.63 x 10^-23 g / unit cell / ( 8 g/cc)

= 4.814x 10^-23 cm³

For FCC, the relation between edge length and radius is as follows:

r = a / (2 sqrt(2))

Volume of cube = a³ = (2x 1.414 x r)³ =  4.814x 10^-23 cm³

r = 1.286 x 10^-10 m

= 0.1286 nm

only 1 question should be answered according to guideines .so pls post remaining question separately.