Matter Lab WorksheetMatter Lab Notes Investigating Physical Changes Name: Date: Researcher Brief: A physical change is a change in the state, shape, or size of matter without changing its identity. Most physical changes are reversible! Part 1: The Basics Circle the correct answer for each question. 1. When a physical change occurs, is a new substance formed? Yes, always No, never Only if it gets hot 2. Which of these is a common example of a physical change? Burning a piece of wood Melting an ice cube Baking a chocolate cake An iron nail rusting Part 2: Change Detective Look at each scenario. Write Physical if it describes a physical change, or Not if it describes a different kind of change. A piece of paper is shredded into tiny strips. Salt is stirred into a glass of water and dissolves. A silver spoon turns black and tarnished over time. Water in a puddle boils away on a hot summer day. A glass window shatters into many small pieces. Matter Lab Notes (Continued) Part 3: Visual Proof Think about an Ice Cube melting. Draw what the molecules might look like as a solid ice cube and as liquid water. Use small circles to represent molecules. Solid Ice Cube Liquid Water Analysis Question Explain why dissolving sugar in water is considered a physical change rather than a chemical change. How could you prove it is still sugar? Part 4: The Reversibility Rule Most physical changes can be undone (reversed). Give an example of a physical change that is easy to reverse and one that is difficult to reverse, even though it's still physical. Easy to Reverse: Difficult to Reverse:
Matter Lab Answer KeyAnswer Key Matter Lab: Physical Changes Teacher Resource Part 1: The Basics No, never. (Physical changes do not create new substances; they only change the appearance or state of the existing substance.) Melting an ice cube. (This is a change of state from solid to liquid water.) Part 2: Change Detective PHYSICAL A piece of paper is shredded into tiny strips. PHYSICAL Salt is stirred into a glass of water and dissolves. NOT A silver spoon turns black and tarnished over time. (Chemical change/Reaction) PHYSICAL Water in a puddle boils away on a hot summer day. (Evaporation/State change) PHYSICAL A glass window shatters into many small pieces. Part 3: Visual Proof & Analysis Molecules Drawing: Students should draw closely packed, organized circles for the Solid Ice and loosely packed, randomly arranged circles for Liquid Water. The individual circles (representing H2O) should look identical in both drawings. Analysis Question: Dissolving sugar is a physical change because the sugar molecules haven't changed into a different substance; they are just spread out between water molecules. You could prove it by evaporating the water (boiling it away), which would leave the solid sugar crystals behind in the container. Part 4: Reversibility Easy to Reverse: Melting ice (refreeze it), mixing sand and water (filter it), or dissolving salt (evaporate water). Difficult to Reverse: Shredding paper or breaking glass. Even though it's still paper or glass, you can't easily put the pieces back together into their original form without complex manufacturing processes.
Change Lab SlidesMatter Masters CHANGE LAB Unlocking the Secrets of Physical Changes What is a Physical Change? A Physical Change is a change that affects the form of a substance but not its chemical identity. No new substance is made. Molecules stay the same. Usually easy to reverse! The "Big Three" Signs Shape Cutting, tearing, folding, or breaking. Size Crushing a can or stretching a rubber band. State Melting, freezing, or evaporating. The Reversibility Rule Most physical changes can be undone. If you freeze water into ice, you can melt it back into water. "If you can get the original substance back exactly as it was, it's a physical change!" Liquid Solid Is it Physical? Dissolving Salt in Water Is it physical? Why? YES Burning a Marshmallow Is it physical? Why? NO Mastered! 1 It stays the same substance. 2 Only the look or state changes. 3 You can usually undo it.
