Chapter 1: Matter, Measurement, and Problem Solving

Vocabulary flashcards covering key terms and concepts from the lecture notes on matter, measurement, and problem solving.

Atom

The smallest chemically indivisible fundamental particle of matter; neutral (chargeless). Examples: He, Ne, Au, Hg.

Molecule

The smallest chemical species that can exist discretely in nature; may contain one or more atoms. Examples: Ne (as listed in notes), O₂, H₂, Cl₂, S₈, H₂O.

Ion

A charged species formed by gaining or losing electrons; may contain one or more atoms. Examples: Na⁺, Cl⁻, SO₄²⁻.

Neutral

Chargeless; having no net electric charge.

Matter

Anything that occupies space and has mass.

Scientific Approach (Scientific Method)

Systematic process of inquiry to understand a phenomenon, solve problems, or address knowledge gaps; involves problem identification, observations, hypotheses, experiments, data collection, analysis, and interpretation.

Observation

Qualitative or quantitative descriptions of phenomena; can occur before, during, or after experiments.

Experiment

A highly controlled procedure designed to generate observations or data to confirm or refute a hypothesis.

Qualitative

Descriptions without numerical measurements.

Quantitative

Descriptions or data that involve numerical measurements.

Hypothesis

A tentative interpretation or explanation of observations; makes predictions that are testable and falsifiable.

Falsifiable

Capable of being proven false by observation or experiment.

Law (Scientific Law)

A brief statement that summarizes past observations and predicts future ones; describes what happens and is testable by experiments.

Conservation of Mass

Matter is neither created nor destroyed in a chemical reaction.

Theory (Scientific Theory)

A well-substantiated explanation of how and why phenomena occur; explains underlying mechanisms and is testable.

Physical States of Matter

Solid, liquid, and gas—the three physical forms matter can take.

Solid

Particles are closely packed in fixed locations; fixed volume and rigid shape; crystalline or amorphous types exist.

Crystalline Solid

A solid with regularly arranged particles.

Amorphous Solid

A solid with irregularly arranged particles.

Liquid

Particles are less tightly packed than in a solid; fixed volume but no fixed shape.

Gas

Particles have a lot of space between them, move freely, are compressible; no fixed volume or shape.

Pure Substance

Matter made of only one component with fixed composition; subdivides into elements and compounds.

Element

A pure substance consisting of atoms of the same identity; cannot be chemically decomposed into simpler substances.

Compound

A pure substance composed of atoms of different elements; can be decomposed into simpler substances.

Mixture

A substance composed of two or more chemically distinct components with varying proportions.

Heterogeneous Mixture

A mixture in which the components can be identified with the naked eye or under a microscope.

Homogeneous Mixture

A mixture whose components cannot be identified with the naked eye or microscope; uniform composition.

Decantation

Physically separating a mixture by pouring off the liquid after the denser component settles.

Filtration

Separating a mixture by passing it through a filter to remove solids from liquids.

Distillation

Separating components by heating a mixture to boil off the more volatile component and condense it elsewhere.