GCSE Chemistry: States of Matter, Mixtures, and Chemical Concepts

Vocabulary flashcards covering states of matter, particle theory, state symbols, mixtures, separation techniques, formulations, chromatography, and foundational chemistry concepts.

The Three States of Matter

The three physical forms in which matter can exist: solid, liquid, and gas.

Simple Particle Model

A model representing particles as small solid spheres to explain state changes such as melting, boiling, freezing, and condensing.

Melting Point

The specific temperature at which melting (solid to liquid) and freezing (liquid to solid) take place.

Boiling Point

The specific temperature at which boiling (liquid to gas) and condensing (gas to liquid) take place.

Limitations of the Particle Model

The simple model assumes particles are solid, inelastic spheres and that there are no forces between them, which does not reflect actual atomic properties.

State Symbols

Notations added to chemical equations to represent physical states: $(s)$ for solid, $(l)$ for liquid, $(g)$ for gas, and $(aq)$ for aqueous.

Aqueous $(aq)$

A state symbol denoting that a substance is dissolved in water.

Mixture

A material consisting of two or more elements or compounds not chemically combined together, retaining the chemical properties of each substance.

Physical Separation Processes

Techniques that separate mixtures without chemical reactions or forming new substances, including filtration, crystallisation, simple distillation, fractional distillation, and chromatography.

Pure Substance (in Chemistry)

A single element or compound not mixed with any other substance, which melts and boils at specific, fixed temperatures.

Pure Substance (Everyday Language)

A substance to which nothing has been added, meaning it remains unadulterated and in its natural state (e.g., pure milk).

Formulation

A mixture designed as a useful product, prepared by blending specific components in carefully measured quantities to ensure required properties (e.g., fuels, paints, medicines, alloys).

Chromatography

A physical process used to separate mixtures and identify substances based on their distribution between a stationary phase and a mobile phase.

$R_f$ Value

The ratio of the distance moved by a compound (centre of spot from origin) to the distance moved by the solvent: $R_f = \frac{\text{distance moved by substance}}{\text{distance moved by solvent}}$.

Pure Compound Chromatographic Behavior

A single compound that will produce a single spot in all solvents during chromatography.

Electron Charge

The relative electrical charge of an electron, which is $-1$.

Isotopes

Atoms of the same element containing the same number of protons but different numbers of neutrons.

Ethane and Ethene

Ethane is a saturated alkane containing single $C-C$ bonds, whereas ethene is an unsaturated alkene containing a double $C=C$ bond.