General Chemistry 1: Matter and States of Matter

Matter

Anything that takes up space and has weight.

Atoms

The smallest unit of an element.

Molecules

Two or more atoms bonded together (e.g., H_2O).

Ions

Charged atoms or molecules.

Avogadro's number

A constant that represents the number of particles per mole, approximately 6.022 \times 10^{23}.

Nanometer

A unit of length equal to 10^{-9} meters; typical atomic scales are 0.1-0.5\mathrm{\,nm}.

Solids

A state of matter with definite shape and definite volume, where particles are tightly packed and vibrate in place.

Liquids

A state of matter with definite volume but adapts to container shape, where particles are close together but can slide past one another.

Gases

A state of matter with no definite shape or volume, where particles are far apart and move freely.

Plasma

An ionized gas with charged particles, formed when atoms lose electrons; the most common state in the universe.

Bose-Einstein Condensate (BEC)

A state of matter occurring near absolute zero where bosons occupy the lowest quantum state, acting as a single quantum entity.

Chemistry

The study of how substances are characterized, what they are made of, and how they transform, including their properties, composition, and structure.

Kinetic concept of matter

The principle that temperature governs particle motion; higher temperature means faster erratic movement on average.

Particle nature of matter

The foundational idea that matter is composed of tiny units (atoms, molecules, ions) whose arrangement and motion determine observable properties.