materials and environment

Draw the structure of BCC and FCC crystals. Explain what the abbreviations mean. Also plot directions in the structures that exhibit anisotropy in terms of density.

b) What is the difference between SEM and TEM? Explain the abbreviations and how the measurement technology works in principle.

c) Calculate the theoretical density of copper (Cu) using the following data:

Theoretical density Ptheory = nA/ VcNA

nA=number of atoms in the unit cell, for nFcc=4; nBcc=2; NHCP=6; A=atomic weight, obtained from tables. VC,BCC = a, VC,FCC = a^3, VC,HCP = 6R^(2)c3 , NA-Avogadro's number

Cu has R=0.1278 nm and a = 2R/2