Physical Properties & Physical Changes — Practice · Grade 6 Science
Chapter: Matter, Mixtures & Water PropertiesWhat this practice covers
By the end of Physical Properties & Physical Changes you should be able to:
- I can measure density and use it to compare two materials.
- I can decide whether a change is physical by asking what substance is present afterwards.
- I can explain why a single property cannot identify an unknown material.
8 questions, written answer and multiple choice, each with a worked explanation.
Vocabulary used: physical property, density, evidence, system boundary, uncertainty.
Problem 1
Answer and explanation
Different substances can share that appearance. Additional appropriate measurements and known source information 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 2
Answer and explanation
No. A physical change can be difficult to undo; evidence about substance identity is more relevant.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 3
Answer and explanation
60 ÷ 20 = 3 g/cm³; size changed but the ratio stayed the same.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 4
Answer and explanation
It distinguishes possibilities that the first property cannot separate; the conclusion should still match the available evidence.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 5
Answer and explanation
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.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 6
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 7
- The largest sample must have the greatest density.
- Every change that is hard to reverse must be chemical.
- physical property: A characteristic measured or observed without changing chemical identity.
- One illustrative result establishes every real condition and needs no further evidence.
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 8
- One illustrative result establishes every real condition and needs no further evidence.
- Every change that is hard to reverse must be chemical.
- The largest sample must have the greatest density.
- density: Mass per unit volume under stated conditions.
Answer and explanation
density: Mass per unit volume under stated conditions.
Mass per unit volume under stated conditions. 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.