135 articles
Bonding & Molecular Structure
Ionic, covalent and metallic bonds, molecular shapes, intermolecular forces and naming compounds.
Which Substances Conduct Electricity, and Why?
Metals conduct, salt solution conducts, solid salt and sugar solution don't. One rule explains them all: you need charged particles that are free to move.
Testing Conductivity to Classify Bonding
A safe low-voltage practical: test solids and solutions in a simple circuit, then use the results to sort each substance into ionic, covalent or metallic.
Covalent Bonding Practice Questions (with Worked Answers)
15 exam-style covalent bonding questions: dot-and-cross for H₂O, NH₃, O₂, N₂ and CO₂, simple vs giant structures, polarity and shape. Marks and full answers.
Covalent vs Metallic Bonding
Covalent and metallic bonding compared for beginners: how electrons are shared in each, the structures they build, and why metals conduct and bend.
Using Electronegativity to Predict Bond Type
Six worked examples that use Pauling electronegativity differences to predict non-polar, polar and ionic bonds, plus the cases where the rule breaks.
Giant Structures Practice Questions (with Answers)
12 exam-style questions on giant covalent, ionic and metallic structures: diamond, graphite, silicon dioxide, sodium chloride and metals, with a marked answer key.
Growing Crystals to Explore Ionic Lattices
A school practical growing copper(II) sulfate or alum crystals from a saturated solution with a seed crystal: principle, method, safety, results and errors.
Ionic Bonding Practice Questions (with Full Answers)
14 exam-style ionic bonding questions with marks: ion charges, formulas like Al₂O₃ and Mg₃N₂, dot-and-cross diagrams, lattices and properties. Full worked answers.
Naming Ionic vs Molecular Compounds: Which Rules to Use and When
Ionic and molecular compounds follow different naming rules. Compare them side by side: -ide endings, Roman numerals, Greek prefixes and the usual traps.
Drawing the Lewis Structure of CO₂, H₂O, NH₃ and CH₄
Step-by-step Lewis structures for carbon dioxide, water, ammonia and methane, plus a bonus methanal example: electron counts, octets, formal charges, shapes.
Metallic vs Ionic Bonding: Same Attraction, Different Structures
Metallic and ionic bonding compared side by side: what holds each together, why metals bend while salts shatter, and how conductivity and melting points differ.
Using Molecular Model Kits in Class: A Practical Teaching Guide
How to teach bonding and shape with model kits: a timed lesson plan building CH₄, H₂O, CO₂, C₂H₄ and an NaCl lattice, plus misconceptions and questions.
Common Mistakes in Naming Compounds
Nine naming myths corrected: prefixes on ionic compounds, what Roman numerals mean, -ide vs -ite vs -ate, hydrates, acids and writing formulas from names.
Polar Covalent Bonds: Unequal Sharing Explained
What a polar covalent bond is, why one atom pulls shared electrons harder, how to mark δ+ and δ−, and the mistakes beginners make with polarity.
Bending Water with a Charged Rod: A Polarity Demo
Bend a thin stream of water with a charged rod, then find out what the demo really shows about polarity, induced charge and why the rod's sign doesn't matter.
Teaching Ionic Bonding Beyond Dot-and-Cross
Move students past dot-and-cross diagrams: a two-lesson ionic bonding guide with lattice models, energy stories, common misconceptions and graded questions.
Teaching Chemical Nomenclature: A Lesson Sequence That Sticks
A teaching guide to naming compounds: two timed lessons, ion-card and sorting activities, the naming errors students make and graded questions to check them.
Four Types of Solids: Ionic, Molecular, Covalent Network and Metallic
Ionic, molecular, covalent network and metallic solids compared side by side: particles, forces, melting points, conductivity and how to tell them apart.
Common Ions and Their Charges: A Reference List
A reference list of common cations and anions with charges — main-group ions, transition metal ions, polyatomic ions and oxyanions — with patterns from the periodic table that make them easy to remember.
Covalent Bonding: Sharing Electrons Explained
Covalent bonding for beginners: why non-metals share electrons, how many bonds each atom forms, single, double and triple bonds, lone pairs, simple vs giant structures and properties.
The Criss-Cross Method for Ionic Formulas
How the criss-cross (swap and drop) method writes ionic formulas quickly, why it works, how to simplify, how to handle polyatomic ions, worked examples, and the cases where it goes wrong.
How to Draw Dot-and-Cross Diagrams
A step-by-step method for dot-and-cross diagrams of covalent molecules and ionic compounds, with worked examples from H₂ to CO₂, NaCl and MgO, and the most common mistakes.
Intramolecular vs Intermolecular Forces
Intramolecular forces (bonds within molecules) vs intermolecular forces (attractions between molecules): definitions, types, strengths, what each controls, and worked examples with water and iodine.
Ionic Bonding: Transferring Electrons Step by Step
Ionic bonding step by step: electron transfer, ion charges from the periodic table, the energy balance and lattice energy, crystal lattices, properties, and how to work out formulas.
"Like Dissolves Like": Solubility and Polarity
What 'like dissolves like' really means: polar and non-polar solvents, the energy and entropy of dissolving, why oil and water don't mix, how soap works, and exceptions to the rule.
How Metallic Bonding Explains Conductivity, Lustre and Malleability
The sea-of-electrons model of metallic bonding and how it explains why metals conduct electricity and heat, shine, bend without breaking, and have high melting points — with data and trends.
How to Name Acids: Binary Acids and Oxyacids
A step-by-step guide to naming acids: binary acids (hydro-…-ic acid), oxyacids from -ate and -ite ions, per- and hypo- prefixes, organic acids, and IUPAC vs traditional names, with practice.
Naming Compounds Practice: 40 Questions with Answers
40 naming and formula-writing practice questions — ionic, polyatomic, transition metal, covalent, acids and hydrates — graded from easy to hard, with a full answer key and explanations.
How to Name Hydrates
How to name hydrates and write their formulas: Greek number prefixes, the dot notation, anhydrous salts, worked examples like CuSO₄·5H₂O, finding x by experiment, and molar mass calculations.
Properties of Covalent Compounds
The properties of covalent substances explained: low melting points and volatility of simple molecules, poor conductivity, solubility patterns, softness, and the very different giant covalent structures.