posted by Josh on .
Gold crystallizes in a face centered cubic structure. Using only a periodic table for refrence, determine the edge length of a gold unit cell. Show all Work.
so you have an atom at each corner. Draw a line through corner to corner along the diagnol. One atom in the center of the face. So the length of the line is 4radii. So the edge of the cell must be .707*4 radii. You can get the radii from the periodic table.
Your teacher might want you to find it from density of gold.
Each corner has 1/8 of an atom, each face 1/2 of an atom. That is 1+3 atoms per cell. You know the mass of each atom (atom mass/avag number), multipy it by 4, that is the mass of each cell.
density= mass/volume= mass/edge^3 solve for edge.