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 11th grader wrote it please
15. The main difference between a physical and chemical change is that a physical change only affects the appearance or state of a substance, while a chemical change involves the formation of new substances with different chemical properties.
16. Examples of reactions that show a chemical change include the formation of a gas, a change in temperature, and the formation of a solid precipitate within a liquid solution.
17. When ice melts, it undergoes a physical change because it simply changes state from a solid to a liquid without any alteration in its chemical composition.