627 articles
All articles — Page 2
Every article in the chemistry library, newest first.
Hydrogen Bonds vs Covalent Bonds: Strength, Length and Role
A side-by-side look at hydrogen bonds and covalent bonds: energies, lengths, what breaks when water boils, and when each one controls a property.
Hydrogen Bonding Misconceptions
Eight hydrogen bonding myths corrected: that any H atom can do it, that it's a covalent bond, that ice traps air, and why water out-boils HF.
Hypervalent Molecules: SF₆, PCl₅ and the Expanded Octet Debate
Do SF₆ and PCl₅ really have 12 and 10 electrons on the central atom? The d-orbital model, why it faded, and the modern 3-centre 4-electron and ionic picture.
Intermolecular Force Myths: What Boiling Really Breaks
Eight intermolecular force myths corrected: boiling breaks bonds, London forces are always weakest, heavier always means higher boiling, and more.
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.
Estimating Percent Ionic Character: Six Worked Examples
Six worked problems on percent ionic character: Pauling's electronegativity formula, working backwards to Δχ, and the dipole-moment method for HCl, HF and NaCl.
Ionic Crystal Structures: Rock Salt, Caesium Chloride, Zinc Blende and Fluorite
The four classic ionic lattices, grouped by coordination: what each looks like, its coordination numbers, which compounds adopt it, and why.
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.
Isomerism in Coordination Complexes: Structural and Stereoisomers
Why one formula can give several different complexes: ionisation, hydrate, linkage and coordination isomers, cis–trans, fac–mer and optical isomers explained.
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.
Lewis Structure of Ozone (O₃) and Resonance, Worked Step by Step
Work out ozone's Lewis structure, formal charges, resonance forms, bond order and bent shape, then compare O₃ with NO₂⁻ and SO₂ in six worked problems.
Lewis Structure of Sulfate: Octet vs Formal Charge
Six worked problems on SO₄²⁻: the all-single-bond and expanded-octet Lewis structures, formal charges, resonance, shape, and what modern bonding theory says.
Lewis Structures of Polyatomic Ions: 6 Worked Examples
Draw Lewis structures for OH⁻, NH₄⁺, CN⁻, NO₂⁻, CO₃²⁻ and SO₄²⁻ step by step: electron counts for charged species, brackets, formal charges and resonance.
Common Ligands: Monodentate, Bidentate and Chelating
A grouped list of 20 common ligands, from water and ammonia to en, oxalate, bipy, porphyrins and EDTA, with donor atoms, charges, denticity and why each matters.
Investigating Melting Points and Bond Types
A safe practical using a water bath and melting-point apparatus to compare wax, stearic acid, sugar, salt and sand, then link each result to its bonding.
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.
Molecular Polarity Practice Questions with Answers
14 exam-style questions on polar and non-polar molecules: bond dipoles, shape and symmetry, from CO₂ and H₂O to XeF₄, NF₃, ozone and dichloroethene.
All 13 VSEPR Shapes with Examples
Every common VSEPR shape from linear to square planar: electron domains, bonding and lone pairs, AXₙEₘ notation, bond angles and a real molecule for each.
Sodium Chloride vs Magnesium Oxide: Why MgO Melts So Much Higher
NaCl and MgO share the same rock-salt structure, yet MgO melts about 2,000 °C higher. Ion charge and ion size explain the gap, side by side.
How to Name Coordination Compounds (IUPAC Method)
A step-by-step IUPAC method for naming coordination compounds: ligand names, prefixes, alphabetical order, oxidation states, -ate endings and bridging ligands.
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.
Pi Stacking and Aromatic Interactions
How flat aromatic rings attract each other: face-to-face, parallel-displaced and T-shaped geometries, the role of quadrupoles, and why the name is debated.
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.
Resonance Structures Practice: 14 Questions with Answers
Resonance practice from nitrite and carbonate to amides, enolates and phenoxide: drawing valid forms, bond orders, major vs minor contributors, full answers.
Sigma vs Pi Bonds Side by Side
Sigma and pi bonds compared: how the orbitals overlap, where the electrons sit, bond strength, rotation, reactivity and how to count them in any molecule.
sp, sp² and sp³ Hybridisation Compared
sp, sp² and sp³ carbon compared side by side: bond angles, shapes, s character, bond lengths, C–H acidity and how to spot each type quickly in an exam.
Teaching Intermolecular Forces: A Lesson Guide
A teaching guide to intermolecular forces: a three-lesson plan with timings, safe demos, boiling-point data tasks, misconceptions to expect, differentiation and questions.
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.