1. Consider the diffusion couple between a pure silver foil and a pure gold foil below. This couple was heated to a temperature of 737 C. After 14 hours it was found that the concentration of silver in gold was 4.5 wt% at 10 um from the interface of the couple. What is the diffusion coefficient for Ag in Au? (Cs hint: Think of the silver atoms as a gas on the left side of the gold foil that is diffusing into the Au. Are the Ag gas-atoms mixed with any other gases? No. So what is Cs?) (Co hint: Co is on the right hand surface of the Au foil. Are there any Ag atoms there at the start?) Ag Au