Properties of Matter — Chapter quiz · Physical Science: Matter, Forces & Energy, Grade 8

Both are oxygen because each has eight protons. A has mass number 16 and is neutral; B has mass number 18 and charge −2. Neutrons change isotope and electrons change charge, while proton count retains element identity. A drawing is a counting model, not a scaled photograph or a literal electron orbit.

Both are oxygen because each has eight protons. A has mass number 16 and is neutral; B has mass number 18 and charge −2. Neutrons change isotope and electrons change charge, while proton count retains element identity. A drawing is a counting model, not a scaled photograph or a literal electron orbit.

Response criteria

• Use the supplied conditions and relevant evidence.
• Explain the scientific mechanism or calculation.
• State a meaningful limitation or testable next step.

Dissolving separates and disperses salt ions in water; it does not convert their nuclei into different elements. Proton counts and element identities remain unchanged.

Dissolving separates and disperses salt ions in water; it does not convert their nuclei into different elements. Proton counts and element identities remain unchanged.

Response criteria

• Use the supplied conditions and relevant evidence.
• Explain the scientific mechanism or calculation.
• State a meaningful limitation or testable next step.

Use the illustrated study titled Molecules and extended structures. Keep the observations, model and conditions separate.

Two water molecules contain four H and two O atoms. A salt patch represents part of an extended arrangement; its bulk Na:Cl ratio is one-to-one rather than a claim that the crystal is a collection of separate NaCl molecules. Retain element/ion labels and note that colors, bonding lines and distances are conventions.

Two water molecules contain four H and two O atoms. A salt patch represents part of an extended arrangement; its bulk Na:Cl ratio is one-to-one rather than a claim that the crystal is a collection of separate NaCl molecules. Retain element/ion labels and note that colors, bonding lines and distances are conventions.

Response criteria

• Distinguish molecule from extended arrangement.
• Count water atoms correctly.
• Explain formula ratio and a model limit.

Atomic number 12; mass number 25; charge +2 in elementary-charge units. Electron loss changes charge, while the 12 protons still determine the element.

Read proton count for atomic number.

Add 12+13 for mass number; compare 12 positive with 10 negative charges.

Atomic number 12; mass number 25; charge +2 in elementary-charge units. Electron loss changes charge, while the 12 protons still determine the element.

Response criteria

• Use the named labels, directions or supplied quantities accurately.
• Connect the visual evidence to the scientific mechanism or calculation.
• State the relevant model conditions or limitation.

Melting and the specified dissolution retain substance identity and are physical; rusting produces different substances and is chemical. Comparable characteristic properties or composition evidence can support a new-substance claim. Some physical changes are hard to reverse, and some reactions can be reversed, so reversibility alone does not classify them.

Melting and the specified dissolution retain substance identity and are physical; rusting produces different substances and is chemical. Comparable characteristic properties or composition evidence can support a new-substance claim. Some physical changes are hard to reverse, and some reactions can be reversed, so reversibility alone does not classify them.

Response criteria

• Use the supplied conditions and relevant evidence.
• Explain the scientific mechanism or calculation.
• State a meaningful limitation or testable next step.

Particles can be mixed too finely to distinguish by eye. A clear sugar solution contains both water molecules and dispersed sugar molecules.

Particles can be mixed too finely to distinguish by eye. A clear sugar solution contains both water molecules and dispersed sugar molecules.

Response criteria

• Use the supplied conditions and relevant evidence.
• Explain the scientific mechanism or calculation.
• State a meaningful limitation or testable next step.

Use the illustrated study titled Mixtures and physical separation. Keep the observations, model and conditions separate.

The separate-component tests and recovery of sand and salt are consistent with a physical combination. The illustrative recovered masses are 4.8+2.9=7.7 g versus 8.0 g originally added, leaving 0.3 g unaccounted for in that collection. Transfer residues, remaining dissolved salt or reading uncertainty can explain a shortfall. Better rinsing, complete collection and repeated matched tests can improve the account; the data do not establish a new compound.

The separate-component tests and recovery of sand and salt are consistent with a physical combination. The illustrative recovered masses are 4.8+2.9=7.7 g versus 8.0 g originally added, leaving 0.3 g unaccounted for in that collection. Transfer residues, remaining dissolved salt or reading uncertainty can explain a shortfall. Better rinsing, complete collection and repeated matched tests can improve the account; the data do not establish a new compound.

Response criteria

• Specify components and a property-based method.
• Use recovered identity and mass evidence.
• Explain a limitation or controlled improvement.

No. Their distinct melting behavior provides another characteristic-property comparison. One matching density is not unique identification.

Compare multiple characteristic properties under stated conditions.

Separate an observed property from an inference of identity.

No. Their distinct melting behavior provides another characteristic-property comparison. One matching density is not unique identification.

Response criteria

• Use the named labels, directions or supplied quantities accurately.
• Connect the visual evidence to the scientific mechanism or calculation.
• State the relevant model conditions or limitation.

A and B each have density 3 g/cm³; the hollow object averages 0.6 g/cm³. A and B tend to sink if no other supporting effect dominates; the hollow object can float if it keeps that effective enclosed volume and displaces sufficient water. Larger mass does not imply larger density, and a leak can change the hollow object’s average density.

A and B each have density 3 g/cm³; the hollow object averages 0.6 g/cm³. A and B tend to sink if no other supporting effect dominates; the hollow object can float if it keeps that effective enclosed volume and displaces sufficient water. Larger mass does not imply larger density, and a leak can change the hollow object’s average density.

Response criteria

• Use the supplied conditions and relevant evidence.
• Explain the scientific mechanism or calculation.
• State a meaningful limitation or testable next step.

The plausible density range can cross the fluid density. More precise measurements or a controlled observation are needed for a confident prediction.

The plausible density range can cross the fluid density. More precise measurements or a controlled observation are needed for a confident prediction.

Response criteria

• Use the supplied conditions and relevant evidence.
• Explain the scientific mechanism or calculation.
• State a meaningful limitation or testable next step.

Use the illustrated study titled Density as identification evidence. Keep the observations, model and conditions separate.

Density is 54/20=2.7 g/cm³. A and C remain consistent while B is inconsistent under matched conditions and adequate measurement precision. Density alone cannot distinguish A from C; choose a safe characteristic-property comparison with supplied reference data, such as solubility for approved samples. Name uncertainty and whether the object is homogeneous.

Density is 54/20=2.7 g/cm³. A and C remain consistent while B is inconsistent under matched conditions and adequate measurement precision. Density alone cannot distinguish A from C; choose a safe characteristic-property comparison with supplied reference data, such as solubility for approved samples. Name uncertainty and whether the object is homogeneous.

Response criteria

• Calculate with correct units.
• Distinguish support from unique identification.
• Choose relevant further evidence and controls.

Volume 12 cm³; density 30/12 = 2.5 g/cm³. Assume no trapped bubbles, spill or incomplete submersion. Density alone does not uniquely identify the substance.

Use the change 47−35, not the final reading.

Divide the independently measured mass by that volume.

Volume 12 cm³; density 30/12 = 2.5 g/cm³. Assume no trapped bubbles, spill or incomplete submersion. Density alone does not uniquely identify the substance.

Response criteria

• Use the named labels, directions or supplied quantities accurately.
• Connect the visual evidence to the scientific mechanism or calculation.
• State the relevant model conditions or limitation.

A precedes B because atomic number counts protons and 11 is less than 12. In these main-group examples, the outer electrons help explain characteristic bonding patterns. Period and group organize patterns, not a guarantee that all neighboring elements behave identically. Shell circles are a simplified electron-energy representation; transition elements and helium need qualifications to simple valence rules.

A precedes B because atomic number counts protons and 11 is less than 12. In these main-group examples, the outer electrons help explain characteristic bonding patterns. Period and group organize patterns, not a guarantee that all neighboring elements behave identically. Shell circles are a simplified electron-energy representation; transition elements and helium need qualifications to simple valence rules.

Response criteria

• Use the supplied conditions and relevant evidence.
• Explain the scientific mechanism or calculation.
• State a meaningful limitation or testable next step.

It names a specific property or behavior and an observation that could support or challenge it, while recognizing the limits of the pattern.

It names a specific property or behavior and an observation that could support or challenge it, while recognizing the limits of the pattern.

Response criteria

• Use the supplied conditions and relevant evidence.
• Explain the scientific mechanism or calculation.
• State a meaningful limitation or testable next step.

Chlorine-37 has 17 protons and 37−17 = 20 neutrons. The decimal 35.45 is an isotope-average mass, not one atom’s particle count.

Use the specified isotope mass number, not the decimal average.

Subtract atomic number from mass number.

Chlorine-37 has 17 protons and 37−17 = 20 neutrons. The decimal 35.45 is an isotope-average mass, not one atom’s particle count.

Response criteria

• Use the named labels, directions or supplied quantities accurately.
• Connect the visual evidence to the scientific mechanism or calculation.
• State the relevant model conditions or limitation.

For a leak-sensitive one-time model test, A’s observed leak record is favorable. For repeated use, B’s larger tested lifetime matters, but one observed leak requires improvement or further testing. Cost and full environmental impacts remain unknown. A recommendation must identify the intended criterion and hard constraints rather than combine unlike measures without a rule.

For a leak-sensitive one-time model test, A’s observed leak record is favorable. For repeated use, B’s larger tested lifetime matters, but one observed leak requires improvement or further testing. Cost and full environmental impacts remain unknown. A recommendation must identify the intended criterion and hard constraints rather than combine unlike measures without a rule.

Response criteria

• Use the supplied conditions and relevant evidence.
• Explain the scientific mechanism or calculation.
• State a meaningful limitation or testable next step.

A weaker load may make one material appear more durable. Comparable loads and methods are needed to attribute a difference to the material or design.

A weaker load may make one material appear more durable. Comparable loads and methods are needed to attribute a difference to the material or design.

Response criteria

• Use the supplied conditions and relevant evidence.
• Explain the scientific mechanism or calculation.
• State a meaningful limitation or testable next step.

Use the illustrated study titled Natural resources and different plastics. Keep the observations, model and conditions separate.

The reuse record supports longer tested service for the rigid container, while the disposal record warns that acceptance depends on product and local processing. Resource origin alone does not establish total impacts. Compare the same task, include cleaning and replacement, and obtain specific production/disposal information. Describe chains and processing as a plausible property explanation rather than proof from the label plastic.

The reuse record supports longer tested service for the rigid container, while the disposal record warns that acceptance depends on product and local processing. Resource origin alone does not establish total impacts. Compare the same task, include cleaning and replacement, and obtain specific production/disposal information. Describe chains and processing as a plausible property explanation rather than proof from the label plastic.

Response criteria

• Connect a synthetic material to a resource and processing.
• Use two different source records.
• Assess benefits, concerns and missing evidence fairly.

A uses 8 initial material-units; B uses 40 for 20 cups. Cleaning energy/water, production, transport, disposal and actual lifetime are omitted, so initial material alone is not a complete impact ranking.

Compare the same amount of service.

Keep the measured raw-material comparison separate from the full life cycle.

A uses 8 initial material-units; B uses 40 for 20 cups. Cleaning energy/water, production, transport, disposal and actual lifetime are omitted, so initial material alone is not a complete impact ranking.

Response criteria

• Use the named labels, directions or supplied quantities accurately.
• Connect the visual evidence to the scientific mechanism or calculation.
• State the relevant model conditions or limitation.