States of Matter, Solutions, and Atomic Structure Vocabulary

Vocabulary flashcards defining core terms in chemistry including states of matter, separation techniques, atomic structure, and chemical chemical equations.

Matter

Anything that has mass and occupies space.

Kinetic Energy

The energy of movement.

Air Pressure

The force exerted by air particles when they collide with surfaces.

Change of State

A physical change in which no new substance is formed.

Melting

A state change process from solid to liquid that occurs when a solid is heated and particles gain kinetic energy.

Freezing

A state change process from liquid to solid that occurs when a liquid is cooled and particles lose kinetic energy.

Evaporation

A state change from liquid to gas that occurs only at the surface of a liquid and can happen at any temperature.

Boiling

A state change from liquid to gas that occurs throughout the liquid at a fixed temperature called the boiling point.

Condensation

A state change process from gas to liquid that occurs when gas loses heat, causing particles to lose kinetic energy and move closer together.

Endothermic Process

A thermal process, such as melting or evaporation, that absorbs heat.

Exothermic Process

A thermal process, such as freezing or condensation, that releases heat.

Pure Substance

A substance containing only one type of particle with a fixed composition and fixed melting and boiling points that cannot be separated by physical methods.

Mixture

A combination of two or more substances physically mixed together where each substance keeps its own properties, melts and boils over a range, and can be separated using physical methods.

Solute

The substance that dissolves in a solvent, such as salt or sugar.

Solvent

The liquid that dissolves the solute, such as water.

Solution

A uniform mixture formed when a solute dissolves completely in a solvent.

Saturated Solution

A solution that cannot dissolve any more solute at a given temperature.

Suspension

A mixture in which insoluble particles are spread through a liquid and settle on standing.

Filtration

A process used to separate an insoluble solid from a liquid by passing the liquid through filter paper.

Residue

The solid left on the filter paper after filtration.

Filtrate

The liquid collected after passing through filter paper during filtration.

Simple Distillation

A process used to separate a solvent from a solution by boiling the solvent, passing the vapour through a condenser, and cooling it back into liquid.

Distillate

The liquid collected after passing through a condenser in simple distillation.

Paper Chromatography

A separation method used to separate coloured substances dissolved in a solvent as different dyes travel at different speeds through paper.

Atom

The smallest particle of an element that retains the properties of that element.

Element

A pure substance made up of only one type of atom, represented by a unique chemical symbol.

Molecule

Two or more atoms chemically joined together, which may contain atoms of the same element or different elements.

Compound

A pure substance formed when two or more different elements chemically combine in a fixed ratio, possessing properties different from its forming elements.

Dalton's Atomic Model

The theory proposed by John Dalton stating that matter consists of indivisible atoms, atoms of the same element are identical, and atoms combine in fixed ratios to form compounds.

Reactants

Substances present before a chemical reaction occurs.

Products

New substances formed after a chemical reaction occurs.

Chemical Symbol

A one- or two-letter abbreviation representing an element, starting with a capital letter followed by a lowercase second letter if present.

Subscript

A small number placed at the lower right of a chemical symbol showing the number of atoms of that element in a formula.

Nucleus

The small centre of an atom containing protons and neutrons that holds almost all the mass of the atom.

Electron Shells

Regions around the atomic nucleus where electrons move.

Proton ($p^+$)

A subatomic particle located in the nucleus with a relative charge of $+1$ and a relative mass of $1$.

Neutron ($n^0$)

A subatomic particle located in the nucleus with a relative charge of $0$ and a relative mass of $1$.

Electron ($e^-$)

A subatomic particle located in electron shells with a relative charge of $-1$ and a relative mass of approximately $\frac{1}{1836}$.

Atomic Number ($Z$)

The number of protons in the nucleus of an atom.

Mass Number ($A$)

The total number of protons and neutrons in the nucleus of an atom, calculated as $A = p + n$.