QUESTIONS Chemical Properties and Changes

Flashcards created for key terms related to physical and chemical properties, changes, and basic concepts in chemistry.

Physical Property

A characteristic of a substance that can be observed without changing its chemical identity, such as density or color.

Chemical Property

A characteristic that can only be observed during a chemical reaction, indicating how a substance behaves in a chemical context.

Quantitative Property

A property that can be measured and assigned a numerical value, such as mass or volume.

Qualitative Property

A property that describes a quality or characteristic of a substance without using numerical values, such as color or smell.

Physical Change

A change that affects one or more physical properties of a substance without altering its chemical composition, like melting or boiling.

Chemical Change

A change that results in the formation of new chemical substances, indicated by color change, gas production, or formation of precipitate.

Impure Substance

A material that contains two or more different substances or mixtures of two or more types of matter.

Pure Substance

A material that has a constant composition and consistent properties throughout; it consists of only one type of particle.

Colloid

A type of mixture where one substance is dispersed evenly throughout another without settling out, like milk.

Heterogeneous Mixture

A mixture that has a non-uniform composition and the individual components can be distinguished.

Homogeneous Mixture

A mixture that has a uniform composition throughout, such as a solution where components are evenly distributed.

Solution

A homogeneous mixture comprised of two or more substances where one substance (solute) is dissolved in another (solvent).

Law of Conservation of Mass

A principle stating that mass is neither created nor destroyed in a chemical reaction.

Element

A pure substance that cannot be broken down into simpler substances by chemical means; it consists of only one type of atom.

Compound

A pure substance formed when two or more elements are chemically bonded together in fixed proportions.

Mixture

A combination of two or more substances in which each substance maintains its chemical identity.

Quantitative Observation

An observation that includes a number or measurement in its description, providing specific information about the subject.

Qualitative Observation

An observation that describes the qualities or characteristics of a substance without numerical values.

Density

The mass per unit volume of a substance, typically expressed in grams per milliliter (g/mL) or kilograms per cubic meter (kg/m³).