Unit 1.1: Analyzing Data & Matter-Properties & Changes (Ch 2 & 3)

Vocabulary flashcards covering key terms from Unit 1.1: Analyzing Data and Matter-Properties & Changes (Ch 2 & 3).

Matter

Anything that has mass and occupies space (volume).

Mass

The amount of matter in an object; typically measured in grams.

Volume

The amount of space that a substance occupies; measured in liters or cubic centimeters.

Density

Mass per unit volume; a physical property used to characterize substances.

Substance

Matter with uniform and definite composition; not a mixture; includes elements and compounds.

Physical Property

A quality or condition of a substance that can be observed or measured without changing its chemical composition.

Color

A physical property describing the appearance (hue) of a substance.

Hardness

A physical property describing how resistant a material is to scratching or indentation.

Odor

A physical property describing a substance’s smell.

Melting Point

The temperature at which a solid changes to a liquid.

Boiling Point

The temperature at which a liquid changes to a gas.

Solubility

The ability of a substance to dissolve in a solvent.

State of Matter

The form in which matter exists: solid, liquid, gas, or plasma.

Solids

Have a definite shape and volume; essentially incompressible.

Liquids

Definite volume, indefinite shape; takes shape of its container; essentially incompressible.

Gases

Indefinite shape and volume; expands to fill container; easily compressed.

Plasma

A superheated gas in which electrons are stripped from nuclei (e.g., the sun, neon signs when on).

Physical Change

A change that alters a substance without changing its chemical composition.

Melting

Solid to liquid (change in state).

Vaporization

Liquid to gas (evaporation/boiling).

Sublimation

Solid to gas, skipping the liquid phase.

Condensation

Gas to liquid.

Freezing

Liquid to solid.

Deposition

Gas to solid.

Mixture

A physical blend of two or more substances.

Heterogeneous Mixture

Not uniform in composition; components are distinct.

Homogeneous Mixture

Uniform in composition; appears the same throughout.

Solution

A homogeneous mixture; components are distributed uniformly (e.g., salt in water).

Distillation

Purification by evaporation and condensation to separate substances by boiling points.

Separation

Physically separating a mixture into its component parts.

Element

The simplest form of matter; cannot be broken down by chemical or physical means.

Compound

Two or more elements chemically combined; can be broken down by chemical reactions.

Chemical Change

A process where one or more substances are transformed into new substances.

Color Change

A change in color indicating a chemical reaction.

Temperature Change

A change in temperature indicating a chemical reaction.

Formation of a Gas

Production of a gas during a chemical reaction.

Formation of a Precipitate

Formation of a solid from dissolved substances in solution.

Qualitative Data

Descriptive, non-numerical data (e.g., color, texture).

Quantitative Data

Numerical data with units (e.g., 25 °C, 10.2 g).

Accuracy

Closeness of a measurement to the true value.

Precision

Closeness of a set of measurements to each other (repeatability).

Accepted Value

The correct value of a measurement as provided by a standard or instructor.

Experimental Value

The measurement obtained in the lab.

Error

The absolute difference between the accepted value and the experimental value: |accepted − experimental|.

Percent Error

(|accepted − experimental| / accepted) × 100%; the error expressed as a percentage.