Matter, Mixtures & Water Properties — Chapter quiz · Science 6: Matter, Energy & Earth Systems, Grade 6
How can particle models and measurements account for matter across changes? Which parts of a stated sand–salt–water mixture can a filter separate, and where does the matter go?
Problem 1
- Every classroom model reproduces reality exactly.
- Solid particles are completely motionless.
- A gas has no mass because it is invisible.
- particle model: A simplified explanation of matter using tiny moving constituents and their arrangement.
Answer and explanation
particle model: A simplified explanation of matter using tiny moving constituents and their arrangement.
A simplified explanation of matter using tiny moving constituents and their arrangement. Melting in the closed sample changes arrangement while retaining its 50 g of water. The open dish loses 6 g from the measured liquid; evaporation is a possible pathway into the air. The water has not been destroyed. Without further records, the mass loss alone does not exclude a spill or specify the evaporation rate over a particular time.
Problem 2
Answer and explanation
Visibility is not the definition of matter. Gas particles have mass and occupy space; a suitable comparison or measurement can show these properties.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 3
- physical property: A characteristic measured or observed without changing chemical identity.
- Every change that is hard to reverse must be chemical.
- The largest sample must have the greatest density.
- Every classroom model reproduces reality exactly.
Answer and explanation
physical property: A characteristic measured or observed without changing chemical identity.
A characteristic measured or observed without changing chemical identity. 48 ÷ 24 = 2 g/cm³. Reshaping changes outline while the modeled material and measured mass/volume remain. It is described as physical because no new substance is formed in this model, not simply because the shape might be restored.
Problem 4
Answer and explanation
No. Blue depends on the observation conditions, and heavy depends on sample size and comparison. Measured properties and additional evidence are needed.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 5
- Any bubbles or color change conclusively prove a chemical reaction.
- chemical change: A change that forms substances with different chemical identities.
- A mass change inside an open container means matter was destroyed.
- Every classroom model reproduces reality exactly.
Answer and explanation
chemical change: A change that forms substances with different chemical identities.
A change that forms substances with different chemical identities. Two A atoms and two B atoms are represented on each side. Their combinations change from A₂ and B₂ to two AB particles. The closed-system mass remains 60 g. This model directly states a rearrangement; a color change alone would not supply the same evidence of substance identity.
Problem 6
Answer and explanation
No. Oxygen from the surroundings enters the material. Account for both the metal and the added oxygen rather than treating the exposed object as a closed system.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 7
- Removing visible particles automatically produces safe pure water.
- A dissolved substance has ceased to exist.
- solution: A mixture with dissolved particles distributed through a solvent at the particle scale.
- Every classroom model reproduces reality exactly.
Answer and explanation
solution: A mixture with dissolved particles distributed through a solvent at the particle scale.
A mixture with dissolved particles distributed through a solvent at the particle scale. After removing 3 g sand, 105 g of salt solution remains in the idealized model. After water enters the air, 5 g salt remains. The water is transferred, not destroyed. Real recovery may be incomplete; these assumptions do not show that the liquid was safe to drink.
Problem 8
Answer and explanation
No. Filter pore size and other treatment properties matter. Visible clarity alone cannot establish removal of dissolved substances or drinking safety.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 9
- Every classroom model reproduces reality exactly.
- The heaviest or largest object must always sink.
- Ice floats because freezing removes its mass.
- buoyancy: The upward force a fluid exerts on an immersed or partly immersed object.
Answer and explanation
buoyancy: The upward force a fluid exerts on an immersed or partly immersed object.
The upward force a fluid exerts on an immersed or partly immersed object. Ice density is 0.9 g/mL. The hull displaces 60 g of modeled water, consistent with buoyancy balancing its weight. A hollow hull can float because of its overall geometry and average density; a compact piece of the same material may behave differently. Neither result is a rule for every temperature or liquid.
Problem 10
Answer and explanation
Ask for mass, volume or displacement, shape, enclosed air, and the liquid’s properties. Size alone does not determine average density or buoyancy.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.