Calculate the energy (in Joule) of attraction between a cation with a valence of +2 and an anion with a valence of -3, the centers of which are separated by a distance of 4.0 nm

Compute the linear density for Copper (FCC) in the [110] direction. The atomic radius of Copper is 0.128nm.

What is the degree of polymerization given that the material is polystyrene?

Compute the linear density for Silver (FCC) in the [111] direction. The atomic radius of Silver is 0.1445nm

Calculate the density (g/cm3) of a polymer having 31.2% crystallinity. The density of fully crystalline and fully amorphous polymer is 1.450 g/cm3 and 1.300 g/cm3 , respectively.

Calculate the density (in g/cm3) of BCC Tantalum with an atomic radius of 0.143 nm.

Which two crystal lattices have the same atomic packing fraction?

Identify this crystal structure. 

What are the Miller indices for the shaded plane shown in the figure? (negative number represents overhead bar)

Compute the percent of ionic character in GaP.