Physical Change
What is a physical change? Give one simple example.
A change that does not make a new substance; example: tearing paper, melting ice.
What is a chemical change? Give one simple example you might see in a kitchen.
A change that makes a new substance; example: baking (heat changes ingredients), rusting, burning.
What two types of materials are most strongly attracted to magnets? Give one example of a common object that is magnetic.
Metals with iron or similar (iron, nickel, cobalt). Example: a paperclip
What are the three main parts of the water cycle? Name them
Evaporation, condensation, precipitation (and often runoff/infiltration included).
What is weathering? What is erosion? Give a one-sentence difference between them.
Weathering breaks rock in place; erosion moves rock and soil from one place to another.
When you melt an ice cube, is that a physical change or a chemical change? Explain why.
Physical change. Ice melts to water; same substance (H2O) just a different state.
Baking a cake involves chemical changes. Name one sign you could observe that tells you a chemical change happened.
Signs: color change, gas bubbles, heat or light produced, new substance (e.g., cake rising and browning).
What are the two ends of a magnet called? What happens when you put two like ends near each other?
North and South poles. Like poles repel; unlike poles attract
What process describes water turning from a liquid into a gas and rising into the air?
Evaporation
Name two agents (things that cause) erosion. Give an example of how each one moves soil or rock.
Water (rain, rivers) and wind are common agents; glaciers and gravity also move material. Water can wash away soil; wind can blow sand and dust.
Name two properties that can change during a physical change (for example: shape, size, state). Give an example for each.
Examples: shape (cutting clay), size (breaking a rock), state (freezing water).
A piece of iron left outside becomes covered in rust. Is rusting a chemical change or a physical change? Explain what new substance forms.
Rusting is chemical; iron reacts with oxygen to form iron oxide (rust).
A piece of iron left outside becomes covered in rust. Is rusting a chemical change or a physical change? Explain what new substance forms.
Use a magnet nearby to see if it moves another object (e.g., see if a paperclip moves or use indirect tests like seeing if a compass needle is affected).
Explain how clouds form using the words evaporation, condensation, and cooling.
Sun heats water (evaporation), water vapor rises and cools, vapor condenses into tiny droplets to form clouds
How can plant roots help reduce erosion? Describe one other human action that might increase erosion.
Roots hold soil in place, reducing erosion; removing plants (deforestation) or overgrazing increases erosion.
A toy robot breaks into many small pieces. Is this a physical change or chemical change? Explain how you know and describe what else could happen to the pieces physically.
Physical change (mechanical break). Pieces remain the same material; they could be glued, ground into dust, or reassembled physically.
List three signs (clues) scientists use to tell if a chemical change has happened.
Signs include color change, temperature change, gas produced (bubbling), formation of a new solid (precipitate), permanent change that can't be reversed easily.
Explain how the Earth acts like a giant magnet. Which end of a compass points north?
Earth has a magnetic field with magnetic north and south; compass needle aligns with Earth's magnetic field so the needle’s north end points toward Earth’s magnetic north.
Describe how precipitation becomes groundwater. Include two ways water moves from the surface into the ground.
Precipitation falls and soaks into the soil (infiltration) or flows into cracks and spaces (percolation), becoming groundwater
A cliff by the ocean slowly moves back (gets smaller) over many years. Explain whether this is weathering, erosion, or both, and why.
Both: waves and salt cause weathering of rock and the pieces are carried away by erosion; continual movement of material leads the cliff to recede.
Describe how salt dissolving in water is a physical change. Then explain one test you could do to show the salt is still the same substance after it dissolves.
Salt dissolving is physical because salt ions disperse but remain chemically salt; evaporate water to recover salt.
Explain why burning a piece of paper is a chemical change. Include what happens to the materials (paper and products like ash, smoke).
Burning paper produces ash and smoke and cannot be turned back into paper — new substances form and energy (heat/light) is released
Two bar magnets are placed end to end with opposite poles near each other. Describe the forces you expect between them. Then describe what happens if you place a small piece of paper between the magnets.
Opposite poles attract (pull together); like poles repel (push apart). A piece of paper between them reduces magnetic force slightly but strong magnets may still attract through thin paper.
Draw a simple sequence (in words) that follows a single drop of water through the whole water cycle: evaporation, condensation, precipitation, runoff, and infiltration. Explain how the drop could move between the steps more than once.
Example sequence: evaporation → condensation → precipitation → runoff → infiltration. The drop can evaporate again and repeat the cycle.
Describe how a river can change its path over time. Use the words sediment, deposition, and meander in your answer.
Rivers carry sediment which can be deposited on inner curves; over time deposition and erosion change the river’s meanders and path.