Lisa found a phase diagram for magnesium (Mg)-lead (Pb) as given below. She has two samples in the oven at 400 °C with different compositions, (1) Mg 90wt%/ Pb 10

wt% and (2) Mg 10 wt%/Pb 90 wt%. Fill the blank below. [blank:X] (1 or 2) will completely melt first if we raise the temperature of oven.