When identifying the types of changes described in the scenarios provided, we can classify them as either physical changes or chemical changes based on the nature of the transformation that occurs.
1. Baking a cake:
- Chemical change: When baking a cake, a chemical change occurs. The ingredients undergo a chemical reaction when exposed to heat, leading to the formation of a new substance with different properties. For example, the batter transforms into a cake with a different texture and taste.
2. Smashing a soda can:
- Physical change: Smashing a soda can results in a physical change. The can undergoes a change in shape and size without altering its composition or chemical properties. This change is reversible through processes like reshaping or melting the metal.
3. Shredding paper:
- Physical change: Shredding paper is a physical change. The paper is mechanically broken down into smaller pieces without changing its chemical composition. The shredded paper retains its properties and can be reassembled or recycled.
4. Chopping wood:
- Physical change: Chopping wood is a physical change. The wood is divided into smaller pieces through a mechanical process, but its chemical composition remains unchanged. The chopped wood pieces retain the characteristics of the original material.
5. Burning wood:
- Chemical change: Burning wood involves a chemical change. As wood burns, it undergoes combustion, reacting with oxygen to produce heat, light, ash, and gases like carbon dioxide and water vapor. The wood is transformed into new substances during this process, indicating a chemical change.
By distinguishing between physical changes (changes in appearance without altering the chemical composition) and chemical changes (reactions leading to the formation of new substances), we can classify the scenarios accordingly.
