627 articles
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Every article in the chemistry library, newest first.
Amorphous vs Crystalline Solids: What's the Difference?
Crystalline solids have long-range order; amorphous solids don't. Compare melting, fracture, X-ray patterns and uses, with quartz vs glass as the key example.
Average Bond Enthalpies: A Reference Table with Explanations
A grouped table of average bond enthalpies in kJ/mol, from H–H to N≡N, with the reason behind each pattern and the difference from bond dissociation energy.
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.
How Bonding Type Predicts Melting Point
Why methane melts at −182 °C and magnesium oxide near 2,850 °C: how ionic, molecular, giant covalent and metallic bonding set melting points.
How Bonding Type Predicts Solubility
Why salt dissolves in water but not in oil, why diamond dissolves in nothing, and how to predict solubility from ionic, molecular, giant covalent or metallic bonding.
The Bonding Triangle: Ionic, Covalent and Metallic as a Continuum
How the van Arkel–Ketelaar triangle places any binary substance between ionic, covalent and metallic bonding using two electronegativity numbers.
Chemical Bonding Exam Questions with Mark-Scheme Answers
14 exam-style chemical bonding questions (41 marks) on ionic, covalent and metallic bonding, shapes, polarity and forces, with a full mark scheme.
Bonding in Benzene: Kekulé vs the Delocalised Model
Why benzene's six C–C bonds are all the same length: the Kekulé structure, its three failures, the delocalised π ring, and the ~150 kJ/mol stability it brings.
Everything About Bonding in Water
From the O–H covalent bonds and 104.5° bent shape to hydrogen bonds, open ice and the 4 °C density peak: how bonding makes water so unusual.
Graphene and Carbon Nanotubes: Structure and Bonding
How one-atom-thick graphene and rolled-up carbon nanotubes are built from sp² carbon, and how their delocalised electrons explain their strength and conductivity.
Chelation and the Chelate Effect Explained
Why ligands that grip a metal with several donor atoms form far more stable complexes: entropy, ring size, EDTA, and chelation in water softening, medicine and biology.
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.
Coordination Chemistry Practice Questions (with Worked Answers)
14 advanced questions on complexes: oxidation states, IUPAC names, d-electron counts, high and low spin, spin-only magnetic moments and isomerism, with worked answers.
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.
Crystal Field Theory: How Ligands Split the d Orbitals
Crystal field theory explained: why ligands split d orbitals, octahedral and tetrahedral patterns, Δo, CFSE, the spectrochemical series and colour.
Metal Crystal Structures: BCC, FCC and HCP Explained
Why most metals crystallise as body-centred cubic, face-centred cubic or hexagonal close-packed, how the three differ, and what that means for their properties.
Delocalised Electrons: Where They Occur and Why They Matter
What delocalised electrons are, where to find them (benzene, carbonate, carboxylates, graphite, metals, dyes) and how they change stability, acidity, colour and conductivity.
Diamond vs Silicon Dioxide: Two Giant Covalent Structures
Diamond and silicon dioxide compared: tetrahedral networks, bond types, hardness, melting behaviour and conductivity, and how to describe each in an exam.
Electron-Deficient Molecules: Boranes and Three-Centre Bonds
How diborane, B₂H₆, holds together with too few electrons: the electron count, 3-centre 2-electron B–H–B bridges, the MO picture, higher boranes and look-alikes.
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.
Fajans' Rules: When Ionic Bonds Become Covalent
How cation size, charge and electron configuration distort anions, why AlCl₃ behaves covalently while AlF₃ is ionic, and the common mistakes with Fajans' rules.
Formal Charge Practice Problems with Full Working
15 formal charge practice problems, from NH₄⁺ and CO to cyanate, fulminate and sulfate, with marks and an answer key that checks every charge against the ion's total.
Fullerenes: Buckyballs and Their Bonding
What C₆₀ and other fullerenes are, why every closed cage needs exactly 12 pentagons, how their bonding differs from graphite, and what they react with.
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.
Graphite vs Graphene: One Layer Makes the Difference
Graphite and graphene compared: the same sp² carbon honeycomb, but stacked layers versus a single sheet. Structure, conductivity, strength and uses side by side.
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.
Halogen Bonding: The Hydrogen Bond's Lesser-Known Cousin
How a σ-hole lets iodine, bromine and chlorine attract electron-rich atoms, why halogen bonds are so linear, and where they matter in crystals and drugs.
High-Spin vs Low-Spin Complexes: How to Tell Them Apart
High-spin vs low-spin complexes compared: Δo versus pairing energy, which d counts are affected, unpaired electrons, magnetism, size, colour and real examples.
Hybridisation Practice Problems (sp, sp², sp³) with Answers
15 exam-style hybridisation problems, from methane to allene and amides, with marks, a full answer key, sigma and pi counts, and tips for the tricky cases.