Question

Use foam balls and toothpicks to create a space-filling model of a simple cubic unit cell. The surfaces of the balls should be touching. On the cube above, draw a cut- away view showing only the atoms (or parts of atoms) inside one unit cell. Pay particular attention to where atoms touch (or not). One atom has been drawn in for you as an example. Number of atoms per unit cell - Coordination number (number of nearest neighbors)- Co A close-packed direction (Ch. 3 glossary) is defined as... Dirtctiens in a Crystal aleng which atoms are in contact Close-packed direction family in simple cubic- Relationship between lattice parameter (a) and atomic radius (r): Coordinate position of largest hole (interstitial position)- Number of nearest neighbors for an atom in the interstitial position - (and draw arrow on cube) Calculate the packing factor for the simple cubic structure (ratio of spherical atom volume to unit cell volume). Note that this is a dimensionless number. Write your answer as a decimal and then convert to percent. Write an equation for the density (p) of a material with a simple cubic structure, in terms of lattice parameter (a), atomic weight (A), and Avagadro's number (NA).

Answer 1