Matter, Properties, Changes, and Substances - Vocabulary Flashcards

Vocabulary flashcards covering key terms from the notes on matter, properties, changes, substances, and mixtures.

Matter

Anything that has mass and takes up space (volume).

Properties

Characteristics used to describe a substance.

Composition

The chemical makeup of a substance.

Extensive properties

Properties that depend on the amount of substance present (e.g., mass, volume).

Intensive properties

Properties that do not depend on the amount of substance present (e.g., color, density, luster, malleability).

Physical properties

Characteristics used to describe matter that do not involve changing its chemical makeup.

Chemical properties

Characteristics that describe how a substance changes or does not change its composition when interacting with other substances.

Physical change

A change that does not involve a change in composition.

Chemical change

A change that involves a change in composition; also called a chemical reaction.

Pure substance

Matter with a single chemical composition; can be an element or a compound.

Element

A pure substance that cannot be decomposed into simpler substances by chemical or physical means.

Compound

A pure substance composed of two or more elements chemically bonded.

Molecule

Group of two or more atoms bonded together; the smallest unit of a chemical compound that can take part in a chemical reaction.

Proton

A positively charged particle in the nucleus of an atom.

Atom

The basic unit of an element; defined by the number of protons in its nucleus.

Mixture

A physical combination of two or more substances; components are not chemically bonded and can be separated.

Homogeneous mixture

A mixture with uniform composition; looks like a pure substance (e.g., a cup of tea with sugar dissolved).

Heterogeneous mixture

A mixture with nonuniform composition; components are visibly different (e.g., chicken noodle soup).

Water (H2O)

A compound made of hydrogen and oxygen; each molecule has 2 hydrogen atoms and 1 oxygen atom.

Solubility

The property describing how well a substance will dissolve in another; dissolution can be physical or chemical depending on context.

Dissolving salt in water vs sugar in water

Salt dissolution in water is argued by some to be a chemical change, whereas sugar dissolution is a physical change.