15. The main difference between a physical and chemical change is that a physical change only alters the physical properties of a substance, such as shape or state, without changing its chemical composition. In contrast, a chemical change results in the formation of new substances with different chemical properties.
16. Three reactions that would demonstrate a substance undergoing a chemical change include:
- Formation of a gas (bubbling or fizzing)
- Change in temperature (exothermic or endothermic)
- Formation of a precipitate (solid forming in a liquid solution)
17. Melting ice is considered a physical change because it only changes the state of water from solid to liquid without altering its chemical composition. The molecules in ice remain the same, just in a different arrangement when melted into water.
Make these answer 1-3 sentences and that a 8th grader wrote it please
15. The main difference between a physical and chemical change is that physical change only changes how something looks or feels, while chemical change makes totally new stuff.
16. When something makes bubbles, gets hot or cold really fast, or makes a solid appear in a liquid, it's probably a chemical change.
17. When ice melts, it's just changing shape from solid to liquid, not its actual stuff inside.