Chemistry in Context: Key Terms (Sections 1.1–1.3)

Vocabulary flashcards covering key terms from Sections 1.1–1.3 of the notes.

Scientific Method

Systematic approach to investigate a question or observation, form a hypothesis, test with experiments, and refine or develop a theory based on results.

Macroscopic Domain

The part of matter that can be perceived by human senses (sight or touch).

Microscopic Domain

The part of matter that is too small to see without a microscope; studied at the atomic/molecular level.

Symbolic Domain

The language of chemical symbols, formulas, and equations used to represent macroscopic and microscopic domains.

Chemistry as Central Science

Chemistry is a central science interconnected with many STEM fields.

Matter

Anything that occupies space and has mass.

Plasma

A gaseous state of matter in which electrons are separated from atoms.

Mass

Amount of matter in an object.

Weight

The force of gravity acting on the mass of an object.

Conservation of Matter

Matter is neither created nor destroyed during chemical or physical changes.

Pure Substance

Matter with a constant composition throughout (includes elements and compounds).

Element

Pure substance that cannot be broken down into simpler substances.

Compound

Pure substance comprised of two or more elements chemically bonded.

Mixture

A combination of two or more types of matter that can be present in varying amounts and can be separated by physical methods.

Heterogeneous Mixture

A mixture whose composition varies from point to point (e.g., Italian dressing).

Homogeneous Mixture

A mixture with uniform composition throughout.

Solution

A homogeneous mixture in which one substance (solute) is dissolved in another (solvent).

Atom

The smallest unit of an element that retains its chemical properties.

Molecule

Two or more atoms bonded together.

Chemical Bond

Forces that hold atoms together in a molecule.

Physical Property

A characteristic observed without changing the substance's chemical composition (e.g., density, color, hardness, melting/boiling point).

Physical Change

A change in which the substance's state or appearance changes without altering its chemical composition (e.g., melting, dissolving).

Chemical Property

The ability of a substance to undergo a chemical change (e.g., flammability, toxicity, acidity, reactivity).

Chemical Change

A process that produces new substances with different properties.

Extensive Property

A property that depends on the amount of matter present (e.g., mass, volume).

Intensive Property

A property that does not depend on the amount of matter present (e.g., temperature).

States of Matter

Solids, liquids, gases, and plasma—distinct forms of matter.