Chemistry: Key Vocabulary from Chapter 1 (Matter, Measurements, and Dimensional Analysis)

Vocabulary flashcards covering core concepts from the notes on matter, properties, units, and measurement.

Chemistry

The science that studies matter, its properties, composition, and the changes it undergoes.

Matter

Anything that has mass and occupies space.

Solid

A state of matter that is rigid and has a definite shape and volume.

Liquid

A state of matter that flows and takes the shape of its container, with a definite volume.

Gas

A state of matter that expands to fill its container, taking both shape and volume.

Mass

A measure of the amount of matter in an object.

Weight

The gravitational force acting on an object's mass; varies with gravity.

Law of Conservation of Matter

The total amount of matter remains unchanged during chemical or physical changes.

Element

A pure substance that cannot be broken down by chemical changes and is listed on the periodic table.

Compound

A pure substance composed of two or more elements chemically bonded; can be decomposed by chemical changes.

Pure Substance

A substance with a fixed composition, either an element or a compound.

Mixture

A combination of two or more substances that can be separated by physical methods and whose composition can vary.

Homogeneous Mixture

A mixture with uniform composition throughout; also called a solution.

Heterogeneous Mixture

A mixture whose composition varies from point to point.

Atom

The smallest unit of an element that retains its properties and can enter into chemical bonds.

Molecule

Two or more atoms bonded together.

Physical Property

A property that does not involve a change in chemical composition (e.g., density, color, melting/boiling points, conductivity).

Physical Change

A change in state or appearance without changing the chemical composition.

Chemical Property

A property that involves changes in chemical composition (e.g., flammability, acidity, reactivity).

Chemical Change

A process that produces one or more new substances.

Intensive Property

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

Extensive Property

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

Density

Mass per unit volume; commonly in kg/m^3, g/cm^3, or g/L.

Volume

The amount of space occupied; SI unit is m^3; common units are L and mL; 1 dm^3 = 1 L; 1 cm^3 = 1 mL.

Temperature

A measure of how hot or cold something is; SI unit Kelvin (K); Celsius degrees are also used.

Time

A measure of duration; SI unit second (s).

Meter

SI base unit for length.

Kilogram

SI base unit for mass.

Second

SI base unit for time.

Kelvin

SI base unit for temperature.

Ampere

SI base unit for electric current.

Mole

SI base unit for amount of substance.

Candela

SI base unit for luminous intensity.

dm^3 (cubic decimeter)

Unit of volume equal to 1 liter; 1 dm^3 = 1 L.

cm^3 (cubic centimeter)

Unit of volume equal to 1 mL; 1 cm^3 = 1 mL.

Liter

Unit of volume equal to 1000 cm^3; 1 L = 1 dm^3.

Conversion Factor

A ratio of two equivalent quantities used to convert between units.

Dimensional Analysis

A method using conversion factors to convert units and solve problems with quantities.

Significant Figures

Meaningful digits in a measurement, including the last uncertain digit.

Exact Numbers

Numbers that are certain and have infinite significant figures (e.g., counting values, defined quantities).

Uncertain Numbers

Numbers that have limited precision due to measurement.

Accuracy

Closeness of a measurement to the true or accepted value.

Precision

Reproducibility of measurements; how close repeated measurements are to each other.

Meniscus

The curved surface of a liquid in a graduated cylinder, read at the bottom.

Measurement

A quantity consisting of a size (magnitude), a unit, and an uncertainty.