Question

The density of chromium is 7.2 g/cm3 if the unit cell is cubic with edge length of 289pm, determine the type of the unit cell

Answer 1

we  know that d= z x m/ a*3 x NA
THEREFORE, 7.2=z x 52 / [289 x 10* -10]*3 x 6.022 x 10*23
z=2.01 therefore, it is BCC[body centered cell ]or ECC[end centered cell]