CHEM 101 Week 1: Matter, Measurement, and Properties

Vocabulary practice flashcards covering fundamental chemistry concepts from CHEM 101 Week 1, including classification of matter, intensive and extensive properties, physical and chemical changes, measurement precision, accuracy, and significant figures.

Intensive property

A property of matter that depends only on the identity of the substance and remains independent of the amount present, such as boiling point, density, and refractive index.

Extensive property

A property of matter that depends directly on the quantity or size of the sample being measured, such as mass and volume.

Physical property

A characteristic of a substance that can be observed or determined without changing the chemical identity or composition of the substance (e.g., color, density, ductility, and malleability).

Chemical property

A characteristic describing a substance's potential to undergo a chemical transformation into one or more new substances, such as reactivity with hydrogen.

Ductility

An intensive physical property that measures the ability of a material to be drawn or stretched out into wires without fracturing.

Malleability

An intensive physical property that characterizes a solid substance's capacity to be hammered or pressed permanently out of shape into thin sheets without cracking.

Refractive index

An intensive physical property that indicates how much the velocity of light is reduced, causing light to bend, when traveling through a given substance.

Element

A pure chemical substance composed of only one kind of atom that cannot be broken down into simpler substances by chemical reactions (e.g., silver and helium gas).

Compound

A pure substance formed from two or more distinct chemical elements bonded together in definite, fixed proportions, such as nitrous oxide ($\text{N}_2\text{O}$) and sodium chloride ($\text{NaCl}$).

Homogeneous mixture

A mixture with a completely uniform composition, appearance, and phase throughout, such as filtered tea, rainwater, or white gold.

Heterogeneous mixture

A mixture that does not possess uniform composition and consists of visibly separate substances or phases, such as salad, freshly squeezed orange juice, or a milkshake.

Physical change

A transformation that alters the form, state, or appearance of a material without modifying its fundamental chemical composition (e.g., dissolving sugar in water, evaporation of alcohol, and melting butter).

Chemical change

A process that involves the rearrangement of atoms and results in the formation of one or more new chemical substances (e.g., burning of gasoline, rusting of an iron bar, and dropping iron into hydrochloric acid).

Accuracy

The degree of closeness of an experimental measurement or series of measurements to the true, accepted reference value.

Precision

The degree of agreement, closeness, or reproducibility among repeated measurements taken under identical conditions.

White gold

A homogeneous mixture (solid metallic alloy) formulated with $75\%$ gold and $25\%$ nickel and zinc.

Significant figures

All digits in an experimentally measured value that are known with certainty, plus one final estimated or uncertain digit.

Exact numbers

Quantities derived from precise counting of individual objects (e.g., $5040\text{ books}$) or from standard unit definitions (e.g., $1\text{ kg} = 1000\text{ g}$), which carry an infinite number of significant figures.