Ion notes

Atom

The fundamental structure of matter that cannot be broken by any chemical means.

Charge neutrality

An atom has no charge because the number of protons matches the number of electrons.

Ion

A charged atom that gives up or gains electrons to achieve a complete outer shell.

Anion

An ion that has gained electrons, resulting in a negative charge.

Cation

An ion that has lost electrons, resulting in a positive charge.

Binary Compound

A compound made of two ions, one being a metal and the other a non-metal.

Ionic Bond

The attraction between oppositely charged ions that holds them together in a compound.

Neutral Compound

A compound where the total charge is zero, resulting from the balance between cations and anions.

Univalent Metal Ions

Ions that can only form one type of charge.

Multivalent Ions

Atoms of certain elements, particularly transition metals, that can form more than one ion.

Roman Numerals in Naming

Used to indicate the charge of multivalent ions when naming compounds.

Polyatomic Ion

An ion made up of more than one element that is covalently bonded together.

Hydroxide

A common polyatomic ion with the formula OH-.

Sulfate

A common polyatomic ion with the formula SO4 2-.

Nitrate

A common polyatomic ion with the formula NO3-.

Ammonium Ion

A polyatomic ion with the formula NH4+.

Naming Polyatomic Ions

The names of polyatomic ions do not change endings when they are part of a compound.