Chemistry

Matter

A substance that has volume and mass, composed of atoms.

Atoms

The building blocks of matter, made up of subatomic particles such as protons, neutrons, and electrons.

Elements

Substances that cannot be broken down into smaller parts by physical or chemical means, consisting of one type of atom.

Compounds

Substances made up of two or more elements that can be separated chemically.

Molecules

The smallest part of a substance, formed when two or more atoms bond together.

Pure Substances

Consist of only one type of particle throughout and have a fixed composition.

Mixtures

Consist of two or more types of particles that are not chemically combined, which can be separated by physical means.

Ions

Atoms or groups of atoms that have a positive or negative charge due to the loss or gain of electrons.

Cations

Positively charged ions formed when an atom loses electrons.

Anions

Negatively charged ions formed when an atom gains electrons.

Octet Rule

Atoms tend to prefer having 8 electrons in their valence shell for stability.

Ionic Bonds

Electrostatic attractions between cations and anions formed due to the transfer of electrons.

Metallic Bonding

The attraction between positively charged metal ions and delocalized electrons in a metallic lattice.

Alloys

Mixtures of two or more elements where at least one is a metal, generally having enhanced properties.

Electron Configuration

The distribution of electrons in an atom's electron shells.

Isotopes

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

Chemical Formula

A representation of a compound that shows the elements and their ratios.

Rutherford’s Model

A model showing that most of the mass of an atom is in the nucleus, with electrons in orbit around it.

Bohr Model

A model proposing that electrons orbit the nucleus in fixed energy levels.

Valence Shell

The outermost shell of an atom containing the valence electrons.

Electron Transfer Diagram

A graphic showing the transfer of electrons from metals to non-metals during ionic bonding.