Atoms, Elements, Compounds

A general term for atoms, molecules, or ions that make up matter.

a model describing matter as tiny particles in constant motion.

A horizontal row of elements in the periodic table.

The principle that the physical and chemical properties of elements repeat in a regular pattern when elements are arranged by increasing atomic number.

A chart that organises all known chemical elements according to their atomic number and properties.

A change that does not produce a new substance.

An insoluble solid formed during a chemical reaction in a solution.

A substance formed during a chemical reaction.

a positively charged particle found in the nucleus.

A material containing only one type of particle with a fixed composition.