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?

To create a cast iron skillet from a mixture of cast iron and steel, two primary phase changes occur during the process: 1. **Melting**: - **Description**: The mixture of cast iron and steel is heated in a furnace to \(1500^{\circ} \mathrm{C}\), which causes the metals to transition from their solid states into a molten (liquid) state. - **Phase Change**: Solid → Liquid 2. **Solidification (Freezing)**: - **Description**: The molten cast iron is poured into a mold. As the metal cools down, it transitions back from the liquid state to a solid state, taking the shape of the mold to form the skillet. - **Phase Change**: Liquid → Solid These two phase changes—**melting** and **solidification**—are fundamental to the casting process used in metalworking to create solid objects from molten materials. **Summary of Phase Changes:** 1. **Melting** (Solid to Liquid) when heating the metal mixture. 2. **Solidification (Freezing)** (Liquid to Solid) when the molten metal cools in the mold. **Answer:** First the metal melts into liquid when heated, then it solidifies (freezes) in the mold to form the skillet.