C3

Physical change

A change in which a substance changes its physical form without forming a new substance.

Chemical change

A change in which a new substance is formed through a chemical reaction.

Reversible reactions

Chemical reactions that can be reversed under certain conditions.

Elements

Substances that cannot be broken down further into simpler substances and are made up of only one kind of atom.

Compounds

Pure substances formed when two or more elements chemically combine.

Solutions

A homogeneous mixture in which a solute dissolves in a solvent.

Atomic structure

Everything is made up of atoms, which are composed of sub-atomic particles such as protons, neutrons, and electrons.

Isotopes

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

Ions

Electrically charged particles formed when atoms gain or lose electrons.

Ionic bonding

Bonding between metals and non-metals where electrons are transferred from the metal to the non-metal to form ions.

Covalent bonding

Bonding between non-metal atoms where electrons are shared between atoms.

Allotropy

The ability of an element to exist in multiple physical forms in the same state.