1. We plan on using thermal evaporation chamber to grow a metal alloy (thin film) with Cu2.0wt% (weight percent) and Al 98.0 wt\%. Source temperature is controlled at 1350K. Please estimate what the target concentrations (weight percent) are in order to maintain the right alloy composition. (Vapor pressure for Al at 1350K is 103 torr, and for Cu at 1350K is 2104 torr. Note that if we change the source temperature for growing this alloy, the target concentration needs an adjustment based on their vapor pressure variations.)