Matter—Properties and Changes

Vocabulary practice flashcards covering physical and chemical properties, states of matter, changes in matter, mixture separation techniques, elements, compounds, and fundamental chemical laws from Chapter 3.

Substance (Pure Substance)

Matter that has a uniform and unchanging chemical composition, such as pure water or sodium chloride.

States of Matter

The physical forms in which all matter that exists naturally on Earth can be classified: solid, liquid, and gas.

Solid

A form of matter that has its own definite shape and volume, is incompressible, and contains tightly packed particles that expand only slightly when heated.

Liquid

A form of matter that flows, has a constant volume, and takes the shape of its container, with particles that are less closely packed than in a solid and able to move past one another.

Gas

A form of matter that flows to conform to the shape of its container and fills the entire volume of its container, characterized by particles that are very far apart and easily compressed.

Vapor

The gaseous state of a substance that exists as a solid or a liquid at room temperature.

Physical Property

A characteristic of matter that can be observed or measured without changing the sample's composition.

Extensive Property

A physical property, such as mass, length, or volume, that is dependent on the amount of substance present.

Intensive Property

A physical property, such as density, boiling point, or scent, that remains independent of the amount of substance present.

Chemical Property

The ability or inability of a substance to combine with or change into one or more other substances.

Physical Change

A transition that alters a substance's appearance or physical properties without changing its chemical composition.

Phase Change

A transition of matter from one state to another, such as boiling, freezing, condensing, or melting.

Chemical Change

A process that involves one or more substances changing into new substances with different compositions and properties; also known as a chemical reaction.

Reactants

The starting substances present before a chemical reaction occurs.

Products

The new substances that are formed as a result of a chemical reaction.

Law of Conservation of Mass

States that mass is neither created nor destroyed during a chemical reaction, meaning $\text{mass}_{\text{reactants}} = \text{mass}_{\text{products}}$.

Mixture

A combination of two or more pure substances in which each pure substance retains its individual chemical properties.

Heterogeneous Mixture

A mixture that does not blend smoothly throughout and in which individual substances remain physically distinct.

Homogeneous Mixture

A mixture that has a constant composition throughout and always exists in a single phase; also referred to as a solution.

Alloy

A solid-solid homogeneous mixture consisting of two or more metals, or a mixture of a metal and a nonmetal in which the metal is the major component.

Filtration

A separation technique that uses a porous barrier to separate a solid from a liquid in a heterogeneous mixture.

Distillation

A physical separation technique for homogeneous mixtures based on differences in the boiling points of the substances involved.

Crystallization

A separation technique that produces pure solid particles of a substance from a solution containing the dissolved substance.

Sublimation

The process during which a solid changes directly into a vapor without melting into a liquid, used to separate solids when only one undergoes this transition.

Chromatography

A technique that separates components of a mixture (mobile phase) based on the ability of each component to travel across the surface of another material (stationary phase).

Element

A pure substance that cannot be broken down or separated into simpler substances by physical or chemical means.

Periodic Table

A grid organizing elements into horizontal rows called periods and vertical columns called groups or families based on repeating patterns of their properties.

Periods

The horizontal rows of elements in the periodic table.

Groups (Families)

The vertical columns of elements in the periodic table that contain elements with similar physical and chemical properties.

Compound

A pure substance made up of two or more different elements that are chemically combined.

Electrolysis

A chemical process that uses an electric current to split a compound, such as water, into its component elements.

Law of Definite Proportions

States that a compound is always composed of the same elements in the same proportion by mass, regardless of the size or source of the sample.

Percent by Mass

The percentage ratio of the mass of each element to the total mass of the compound, calculated as $\text{percent by mass} = \frac{\text{mass of element}}{\text{mass of compound}} \times 100$.

Law of Multiple Proportions

States that when different compounds are formed by a combination of the same elements, different masses of one element combine with the same relative mass of the other element in a ratio of small whole numbers.