STM 005 – Fundamental Concepts of Matter & Measurement

Vocabulary flashcards covering key terms and definitions from Modules 1–5 of the STM 005 lecture notes.

Chemistry

The study of matter, its properties, and the changes it can undergo.

Matter

Anything that has mass and occupies space.

Particle Theory of Matter

Model stating that all matter is made of tiny particles that have spaces between them and are always moving.

Solid

State of matter with definite shape and volume; particles tightly packed and only vibrate.

Liquid

State of matter with definite volume but variable shape; particles close but able to slide past each other.

Gas

State of matter with neither fixed shape nor volume; particles far apart and moving rapidly.

Plasma

High-energy state containing freely moving ions and electrons; common in stars and lightning.

Bose–Einstein Condensate (BEC)

State of matter formed at extremely low temperatures where atoms behave as one quantum entity.

Phase Change

Transformation between states of matter caused by adding or removing heat (e.g., melting, vaporization).

Pure Substance

Material made of only one kind of particle—either an element or a compound.

Element

Pure substance consisting of only one type of atom (e.g., O₂, Au).

Compound

Pure substance composed of two or more elements chemically combined in fixed ratios (e.g., H₂O, NaCl).

Mixture

Physical blend of two or more substances with variable composition.

Homogeneous Mixture

Mixture that looks uniform throughout; components not visually distinguishable (e.g., salt water).

Heterogeneous Mixture

Mixture with visibly different parts or phases (e.g., sand in water).

Solution

Homogeneous mixture with very small particles (<1 nm) that do not scatter light.

Colloid

Mixture with medium particles (1–1000 nm) that scatter light (Tyndall effect).

Suspension

Mixture with large particles (>1000 nm) that settle on standing and are easily seen.

Organic Compound

Carbon-containing compound such as sugars, fats, and proteins.

Inorganic Compound

Compound generally lacking carbon, e.g., salts, acids, bases.

Acid

Substance that donates hydrogen ions (H⁺); pH < 7.

Base

Substance that accepts hydrogen ions; pH > 7.

Physical Property

Characteristic observable without changing chemical identity (e.g., color, melting point).

Intensive Property

Physical property independent of sample size (e.g., density).

Extensive Property

Physical property dependent on amount of matter (e.g., mass, volume).

Chemical Property

Ability of a substance to undergo a chemical change (e.g., iron rusting).

Physical Change

Change in appearance or state without altering chemical composition (e.g., freezing).

Chemical Change

Process that forms new substances with different compositions (e.g., combustion).

Diffusibility

Ability of particles to spread and mix with others, as perfume filling a room.

Brittleness

Tendency of a material to break or shatter easily.

Thermal Conductivity

Ability of a substance to transfer heat.

Compressibility

Ability of a material to decrease in volume under pressure.

Elasticity

Ability to return to original shape after deformation.

Capillarity

Ability of a liquid to flow through narrow spaces against gravity.

Ductility

Capability of being drawn into thin wires without breaking.

Malleability

Capability of being hammered or rolled into thin sheets.

Viscosity

Resistance of a liquid to flow; higher viscosity means slower flow.

Flexibility

Ability to bend without breaking.

Accuracy

Closeness of a measured value to the true or accepted value.

Precision

Closeness of repeated measurements to one another, independent of accuracy.

Volume (formula)

Calculated as length × width × height for regular solids.

Density (formula)

Mass divided by volume (ρ = m / V).

Significant Figures

Digits in a measurement that convey its precision according to set rules.

Scientific Notation

Expression of numbers as N × 10ⁿ to handle very large or very small values.