Name Date Grade Period Rusty Nails Grade Eight Science Lab Pre-Lab Questions Directions: Answer the following questions in complete sentences. 1. What is a chemical change? 2. How is a chemical change different from a physical change? 3. Is the rusting of iron a chemical or a physical change? How do you know? 4. What are three things needed in order for rust to occur? 5. Read the procedure and develop a hypothesis: which nail(s) will rust? Why? Which nail(s) will not rust? Why? Materials 3 Test tubes 3 Rubber stoppers Test tube rack 3 Iron nails Distilled water Vegetable Oil Baking soda Salt Procedure 1. Place one clean, dry nail in each of the three test tubes. 2. Fill the first test tube half way with distilled water. Add oneteaspoon salt. Seal the test tube with a rubber stopper. 3. Fill the second test tube half way with boiled water. Place a thin layer of oil on top of the water. Seal the test tube. 4. Fill the third test tube about a quarter of the way with baking soda. Seal the test tube. Observations On day one, sketch an image of the nails in the test tubes below. Be sure to add color to your image. On day two, sketch an image of the nails in the test tube below. Add color to your image. Take notes about any of the changes you observe. _________________________________________________________________ _________________________________________________________________ _________________________________________________________________ Analysis/Conclusion 1. What did you observe in each of the three test tubes? 2. Is the formation of rust considered a “new substance?” Why/why not? 3. Why did some of the nails rust, while others did not (think about what may have been absent from some of the test tubes)? 4. Based on this experiment, what factors are necessary for rust to form on iron? Use evidence from this experiment support your statement.