Using crystal structure to calculate Density
Calculate the density of iron in grams per cubic centimeter (g/cm^3) at 25 degree, given that its crystal structure is based on a bcc unit cell, and and that the edge length of the cell is 287 pm.
COLLECT AND ORGANIZE We are asked to calculate a density of iron knowing its unit-cell geometry and edge length. We assume that the density of the unit cell is the same as the density of solid Fe. The face that Fe has a bcc unit cell means that there are 2 atoms of Fe per cell. Recall that density is the ratio of mass to volume. The molar mass of Fe is 55.84 g/mol. The volume of a cubic cell is the cube of its edge length : V=l^3