States of Matter
States of Matter 100 — What state of matter has a definite shape and a definite volume?
States of Matter 100 — Solid.
Pure Substances & Mixtures 100 — What do we call a material that has the same composition and physical properties throughout (example: distilled water)?
Pure Substances & Mixtures 100 — Pure substance (distilled water). 2
Density & Layering 100 — Density is the amount of what in a given volume?
Density & Layering 100 — Mass.
Physical vs Chemical Changes 100 — Is melting ice a physical change or a chemical change? Explain briefly.
Physical vs Chemical Changes 100 — Physical change (melting changes shape/state but not composition).
Energy, Forces & Waves 100 — What kind of energy is stored because of an object’s position (example: a rock at the top of a hill)?
Energy, Forces & Waves 100 — Potential energy.
200 — Which state of matter has particles that move fastest and have the most kinetic energy?
200 — Gas (particles move fastest; greatest kinetic energy).
200 — What is the main difference between a mixture and a compound?
00 — A compound is chemically combined (new substance); a mixture is physically combined (components keep their own properties).
200 — If you pour oil and water into a container, which one floats on top and why?
200 — Oil floats on water because oil is less dense than water.
200 — Name two signs that a chemical change has occurred.
200 — Signs: bubbles/gas production, temperature change, color change, formation of a solid (precipitate), odor change, light or smoke.
200 — What is a force?
200 — A push or a pull.
300 — Describe how the shape and volume of a liquid compare to those of a solid and a gas.
300 — Liquids have no definite shape but have definite volume; solids have definite shape and volume; gases have neither definite shape nor volume.
300 — Give one example of a homogeneous mixture and one example of a heterogeneous mixture.
300 — Homogeneous example: salt water; heterogeneous example: salad, oil and vinegar.
300 — Three liquids are poured into a beaker and form three layers. Where will the most dense liquid be found?
300 — The most dense liquid will be at the bottom.
300 — Burning wood produces ash and smoke. Is this a physical or chemical change? Explain one sign that confirms your answer.
300 — Chemical change; signs include smoke, ash (new substances), heat release.
300 — Describe how potential energy and kinetic energy change for a roller coaster car as it goes down a hill.
300 — As the car goes down, potential energy decreases while kinetic energy increases; total energy (ignoring friction) remains the same.
400 — Explain how increasing the energy of particles can change the state of matter. Give one example.
400 — Adding energy (heat) increases particle motion, causing solids → liquids (melting) or liquids → gases (evaporation); e.g., ice melting into water when heated.
400 — Explain why salt dissolved evenly in water is considered a homogeneous mixture, but a salad dressing with oil and vinegar is heterogeneous.
400 — Salt dissolves into individual ions that spread evenly (single phase). Oil and vinegar do not mix and form separate layers (different phases), so heterogeneous.
400 — You have two liquids: A with density 0.8 g/mL0.8 g/mL and B with density 1.2 g/mL1.2 g/mL. If mixed carefully, which will float on top? Explain using density.
400 — Liquid A (density 0.8 g/mL0.8 g/mL) will float on top of B (density 1.2 g/mL1.2 g/mL) because it is less dense.
400 — Sugar heated until it turns brown or black has changed into new substances. Which type of change is this and list two signs that show it happened.
400 — Chemical change; signs: color change, new substance formed (carbon/char), possibly odor and temperature change.
400 — Explain how radiant energy from the Sun becomes chemical energy in plants. Name the process.
400 — Photosynthesis: plants use radiant energy to make chemical energy (glucose); radiant → chemical energy via photosynthesis.
500 — A sample of matter is at room temperature and holds its shape unless force is applied; after heating it becomes a flowing substance with a definite volume. Identify the initial state, the state after heating, and name the process.
500 — Initial: solid; after heating: liquid; process: melting.
500 — A substance is made of two elements chemically combined. Is it a mixture or a compound? Explain how this affects its properties compared to the original elements.
500 — Compound. Its properties differ from the original elements because chemical bonds change composition.
500 — Describe how you could use density to identify whether an unknown liquid is more or less dense than water, including one measurement or observation you would make.
500 — Place a known amount of the unknown liquid on water or measure mass and volume to calculate density density=massvolumedensity=volumemass and compare to water (water ≈ 1.0 g/mL1.0 g/mL).
500 — A student mixes two clear solutions and notices bubbles form and the temperature drops. Explain why this shows a chemical change and describe two pieces of evidence the student observed.
500 — Chemical change; evidence: bubbles (gas formed) and temperature change (energy change), indicating new substances formed.
500 — Describe the difference between a longitudinal wave and a transverse wave. Give one real-world example of a longitudinal wave.
500 — Longitudinal: particles move parallel to wave direction (sound waves, spring/compression waves). Transverse: particles move perpendicular (water surface waves, light). Example longitudinal: sound waves in air or compressions in a slinky.