Practice Quiz: Properties of Substances

Color is a physical property because it describes the appearance without changing the substance's chemical composition. Physical properties can be measured or observed without altering the chemical identity of the material.

A solid maintains a fixed shape and volume because its particles are tightly packed in a regular pattern. This stability distinguishes solids from liquids and gases.

Evaporation is the process by which a liquid turns into a gas, typically occurring at the surface. This change is physical because the chemical composition of the substance remains the same.

Density is defined as mass per unit volume and is a key property used to identify and characterize substances. It gives a direct indication of how compact the matter in a substance is.

Mass remains constant during a physical change, such as melting or boiling, because the quantity of matter does not change. Other properties like volume or shape may change with the state, but mass is conserved.

Rust formation on iron involves the chemical reaction of iron with oxygen to form iron oxide, a new substance. This distinguishes it from physical changes like melting or dissolving.

Color changes are common during chemical reactions as new compounds with different light-absorbing properties are formed. This makes color a useful indicator of chemical change.

Chemical properties describe how a substance interacts with other chemicals and undergoes transformations, which involves its composition. In contrast, physical properties can be observed without changing the substance's chemical identity.

Freezing water is a process where water changes its state from liquid to solid without altering its chemical structure. This reversible change is a classic example of a physical change.

Salt dissolves in water because the polar water molecules interact with the charged ions in salt, effectively separating them. This ionic interaction allows salt to disperse uniformly throughout the water.

Mass is the measure of the amount of matter in a substance and remains constant regardless of its location. It is a fundamental property used in scientific measurements and identification.

When a liquid is heated, its molecules move faster and tend to occupy more space, which decreases its density. This relationship between temperature and density is a common physical behavior in liquids.

During a phase change from solid to liquid, the mass of a substance remains constant even though its volume and shape may change. This demonstrates the conservation of matter during physical changes.

Reactivity is a chemical property that describes how a substance behaves when it comes into contact with another chemical, such as an acid. This property helps determine the nature and extent of chemical reactions.

Electrical conductivity is an inherent physical property of a material that depends on the arrangement and mobility of electrons. It is used to determine how well a substance can transmit electrical current.

Stronger intermolecular forces require more energy to overcome, resulting in a higher boiling point for the substance. This relationship is fundamental in understanding how molecular interactions affect physical properties.

Melting point is a specific physical property that often varies between substances, even when their densities are similar. This makes it a reliable criterion for distinguishing between substances under controlled conditions.

The presence of impurities disrupts the ordered structure needed for a solid to form, leading to a depression in the freezing point. This phenomenon, known as freezing point depression, is commonly observed in solutions.

Viscosity reflects the internal friction of a fluid, which is directly influenced by the strength of intermolecular forces and molecular structure. Higher viscosity typically indicates stronger attractive forces between molecules.

Temperature is a key factor in the dissolution process, as higher temperatures typically increase solubility by enhancing molecular interactions. This effect is attributed to the increased kinetic energy of the solvent molecules.