CHM 113 - Module 1: Matter, Energy & Measurement

Vocabulary flashcards covering matter, classification, physical vs. chemical properties/changes, intensive vs. extensive properties, unit conversions, temperature, significant figures, and density.

Matter

Anything that has mass and occupies space.

Solid

A state of matter with a fixed shape, fixed volume, and packed, ordered particles.

Liquid

A state of matter that takes the shape of its container, has a fixed volume, and contains packed particles with more movement.

Gas

A state of matter that takes both the shape and volume of its container, with particles that are far apart.

Pure substance

Matter consisting of only ONE substance that cannot be separated physically.

Element

A pure substance containing only ONE type of atom (e.g., $O_2$).

Compound

A pure substance made of 2+ different elements chemically bonded in a fixed ratio (e.g., $H_2O$).

Mixture

Matter consisting of 2+ substances physically combined that can be separated physically.

Homogeneous mixture

A mixture that is uniform throughout (e.g., salt water).

Heterogeneous mixture

A mixture whose composition varies throughout (e.g., wet sand).

Physical Property

A property that can be observed without changing the substance's identity (e.g., color, density, mass, volume, melting point, boiling point, hardness).

Chemical Property

A property that describes the ability of a substance to become a different substance (e.g., flammability, reactivity, corrosiveness).

Physical Change

A change in which the substance's identity does NOT change and the same substance remains afterward (e.g., melting, freezing, boiling, cutting, most dissolving).

Chemical Change

A change in which a new substance forms (e.g., burning, rusting/oxidation, decomposition).

Intensive Property

A property that does NOT depend on the amount of substance present (e.g., density, color, melting point, boiling point, hardness).

Extensive Property

A property that DOES depend on the amount of substance present, where more substance causes the property to get bigger (e.g., mass, volume, internal energy).

Dimensional Analysis

A technique for converting units by placing unwanted units on the opposite side of a conversion factor so that they cancel out.

Temperature Conversions

Formulas relating Celsius and Kelvin: $K = {}^\bullet\text{C} + 273.15$ and ${}^\bullet\text{C} = K - 273.15$.

Density

An intensive physical property calculated as mass divided by volume ($D = \frac{m}{V}$), commonly measured in units of $g/mL$ or $g/cm^3$.

Significant Figures: Nonzero Numbers

Rule stating that nonzero numbers ALWAYS count as significant figures (e.g., 456 has 3 sig figs).

Significant Figures: Zeros Between Nonzero Numbers

Rule stating that zeros positioned between nonzero numbers always count as significant figures (e.g., 1002 has 4 sig figs).

Significant Figures: Leading Zeros

Rule stating that leading zeros NEVER count as significant figures (e.g., 0.0045 has 2 sig figs).

Significant Figures: Trailing Zeros

Rule stating that trailing zeros count IF a decimal point is present (e.g., 1.500 has 4 sig figs, 0.005060 has 4 sig figs, while 1500 normally has 2 sig figs).