GPS Chapter 2: Properties Of Matter

A physical property refers to any characteristic of a substance that can be observed or measured without altering its composition. It includes properties such as color, density, melting point, boiling point, and conductivity. These properties help in identifying and describing substances without undergoing any chemical changes. Therefore, the correct answer is physical property.

Squeezing juice from an orange is a physical change because the state of the orange changes from whole to liquid, but the chemical composition of the orange remains the same. The process of squeezing physically alters the orange, but it does not cause any chemical reactions or create new substances.

Density is commonly used to test the purity of a substance because it is a physical property that is specific to each substance. Pure substances have a specific density value, and any deviation from this value indicates the presence of impurities. By measuring the density of a substance, one can determine its purity as well as identify any contaminants or foreign substances that may be present.

A compound is a substance made from two or more simpler substances in a fixed proportion. This means that the elements in a compound are combined in specific ratios and cannot be separated by physical means. Compounds have unique properties different from the elements they are composed of, and they can only be broken down into their constituent elements through chemical reactions.

Flammability is not a physical property because it refers to the ability of a substance to burn or ignite. Physical properties, on the other hand, are characteristics that can be observed or measured without changing the substance's chemical composition. Density, boiling point, and conductivity are all physical properties as they can be determined without altering the substance's chemical nature.

A chemical change can be identified when a new substance is formed. This is because a chemical change involves the rearrangement of atoms and molecules, resulting in the creation of different substances with new chemical properties. Other factors such as visible changes, irreversibility, or temperature changes can also be indications of a chemical change, but they are not always definitive. The formation of a new substance, however, is a clear indicator that a chemical reaction has occurred.

Melting is not a common type of evidence for a chemical change because it is a physical change, not a chemical change. In a chemical change, the substance undergoes a chemical reaction and forms new substances with different properties. In the case of melting, the substance simply changes from a solid state to a liquid state without any change in its chemical composition. Therefore, melting is not considered as evidence for a chemical change.

Salt water is an example of a solution because it is a homogeneous mixture where salt (a solute) is dissolved in water (a solvent). In a solution, the components are evenly distributed and cannot be easily separated by physical means. In the case of salt water, the salt particles are dispersed throughout the water molecules, forming a uniform mixture.

Viscosity refers to the measure of a liquid's resistance to flow. It is not related to the speed at which a liquid flows, but rather the tendency of a liquid to resist flowing. Therefore, the given answer is incorrect.

Suspensions can be separated with a filter because they contain larger solid particles that are not dissolved in the liquid. When a suspension is poured through a filter, the liquid passes through while the solid particles are trapped by the filter, resulting in the separation of the two components. On the other hand, colloids, compounds, and homogeneous mixtures have smaller particles that are either dissolved or evenly distributed throughout the mixture, making it difficult to separate them using a filter.