Ionic Compounds & Equations Lecture

Vocabulary flashcards covering key terms and concepts from the lecture on ions, ionic compounds, naming conventions, lattice properties, and related chemical principles.

Acknowledgement of Country

Respectful recognition of the Wurundjeri people of the Kulin Nation as traditional owners, first scientists, and storytellers.

Ion

An atom or group of atoms that has gained or lost electrons and carries an electric charge.

Cation

A positively-charged ion formed by the loss of one or more electrons.

Anion

A negatively-charged ion formed by the gain of one or more electrons.

Monatomic

Consisting of single, unbonded atoms (e.g., Ne).

Molecule

Two or more atoms chemically bonded together; may be same or different elements.

Molecular Element

A molecule made of identical atoms (e.g., O₂, N₂).

Molecular Compound

A molecule containing two or more different elements (e.g., H₂O, C₆H₁₂O₆).

Lattice Compound

A substance whose atoms/ions form an extended 3-D network (e.g., NaCl crystal).

Ionic Compound

A neutral substance composed of cations and anions held together by electrostatic attraction.

Predicting Ionic Charges

Using periodic table groups: 1⁺ (Group 1), 2⁺ (Group 2), 3⁺ (Group 13), 3⁻ (Group 15), 2⁻ (Group 16), 1⁻ (Group 17).

Transition Metal Ion

Metal ion (d-block) that can exhibit multiple possible charges (e.g., Fe²⁺, Fe³⁺).

Roman Numerals (in naming)

Notation that indicates the specific charge of a metal with variable oxidation states, e.g., Iron (III) chloride.

Polyatomic Ion

A tightly bound group of atoms acting as a single charged species (e.g., SO₄²⁻).

Ammonium

NH₄⁺; common polyatomic cation.

Hydroxide

OH⁻; polyatomic anion responsible for basic solutions.

Carbonate

CO₃²⁻; polyatomic anion found in limestone and shells.

Hydrogen Carbonate (Bicarbonate)

HCO₃⁻; amphiprotic polyatomic anion in blood buffering.

Nitrate

NO₃⁻; polyatomic anion present in fertilizers.

Sulfate

SO₄²⁻; polyatomic anion in gypsum and Epsom salt.

Phosphate

PO₄³⁻; polyatomic anion essential for DNA and ATP.

Swap and Drop

Method for writing ionic formulas: swap the magnitude of ion charges and use them as subscripts, then simplify.

Charge Neutrality

Principle that total positive and negative charges in an ionic compound must balance to zero.

Parentheses in Formulas

Used around polyatomic ions when more than one is needed, e.g., Al₂(SO₄)₃.

Ionic Bonding Model

Explains ionic substances as lattices of alternating cations and anions held by electrostatic forces.

Lattice Structure

Regular 3-D arrangement where each cation is surrounded by several anions and vice-versa.

Hardness (Ionic)

Strong ionic bonds make crystals difficult to scratch or deform.

Brittleness (Ionic)

When stress shifts layers, like-charged ions align, repel, and the crystal shatters.

High Melting Point

Large energy needed to overcome strong ionic attractions, so ionic solids melt at high temperatures.

Solubility in Water (Ionic)

Water molecules surround individual ions, breaking the lattice and allowing dissolution.

Electrical Conductivity of Ionic Substances

Conduct only when molten or aqueous because free-moving ions carry charge.

Chemical Naming Rule

Write cation name first, anion second; change anion ending to –ide unless it is polyatomic.