A worker takes a mixture of cast iron and steel metal and places it inside a furnace that reaches \( 1500^{\circ} \mathrm{C} \). The molten cast iron is poured into a mold. The mold is hung out to dry. Later, the worker removes a cast iron skillet from the mold. What two phase changes occure in order to make the skillet?

First, the worker's heating of the cast iron and steel mixture in the furnace induces melting, which is a phase change from solid to liquid. This occurs at high temperatures when the solid metals become molten and can be poured into the mold. After pouring the molten cast iron into the mold, the next phase change happens as the molten metal cools down outside the furnace, solidifying back into its original solid state. This cooling process allows the cast iron to take the shape of the mold, resulting in the final cast iron skillet that is ready for use.