627 articles
All articles — Page 14
Every article in the chemistry library, newest first.
Monosaccharides: Glucose, Fructose and Galactose
The structures and chemistry of the simple sugars: aldoses and ketoses, trioses to hexoses, glucose, fructose and galactose compared, isomers and D/L forms, ring formation, reducing properties and roles in the body.
Naming Salts from Their Parent Acids
How to name any salt: the metal comes first, the acid decides the ending. Chlorides, sulfates, nitrates, carbonates, phosphates, ethanoates, hydrogen salts and transition metal Roman numerals, with practice.
Neurotransmitters: The Chemistry of the Brain
A list of the brain's main chemical messengers, grouped by chemical type (amino acids, monoamines, acetylcholine, peptides, gases and purines), with their structures, jobs, how drugs affect them, and how synapses turn electrical signals into chemistry.
Nuclear Magnetic Resonance: How MRI and NMR Work
The physics and chemistry of NMR: nuclear spin, magnetic fields and radio waves, chemical shift, shielding, TMS, how NMR reveals molecular structure, and how the same principle creates MRI scans in hospitals.
Noble Gas Shorthand: Writing Electron Configurations the Fast Way
How to write electron configurations in noble gas (condensed) notation: choosing the right core, step-by-step method, worked examples from sodium to lead, using the periodic table as a map, ions, why the core is chemically unimportant, ordering conventions, and practice questions with answers.
Radial and Angular Nodes in Atomic Orbitals
What nodes in atomic orbitals are, how to count radial and angular nodes with the formulas n − l − 1 and l, worked examples from 1s to 5f, nodal planes and cones, radial probability graphs, why nodes raise orbital energy, phases and why nodes matter for bonding and spectroscopy.
Acid–Base Chemistry Without Water
How acids and bases behave in solvents like liquid ammonia, glacial ethanoic acid, sulfuric acid and molten salts: solvent self-ionisation, the solvent-system definition, levelling and differentiating solvents.
The Band of Stability: Why Some Nuclei Are Stable
Why is carbon-12 stable but carbon-14 radioactive? A guide to the band of stability: neutron-to-proton ratios, magic numbers, even–odd effects, and how a nucleus's position predicts its decay mode.
Nucleic Acids: DNA and RNA Chemistry
The chemistry of nucleic acids: nucleotides and their three parts, the five bases, sugars, phosphodiester bonds and the sugar–phosphate backbone, 5′ and 3′ ends, why nucleic acids are acidic, and what DNA and RNA do.
Ocean pH: Past, Present and Future
How the ocean's carbonate system sets seawater pH near 8.1, how absorbing carbon dioxide is lowering it, why a 0.1 drop matters, and what ocean acidification means for shells, corals and the food web.
The Octet Rule: Why Atoms "Want" Eight Electrons (and When They Don't)
What the octet rule says, where it came from (Lewis and Langmuir), why eight electrons correspond to filled s and p subshells, how it predicts ionic charges and covalent bonding, worked Lewis-structure examples, the duet rule for hydrogen, why 'wanting' is the wrong language, and a preview of the main exceptions.
How to Draw Orbital Box Diagrams Step by Step
A step-by-step method for drawing orbital box (arrows-in-boxes) diagrams: setting out boxes for each subshell, applying the Aufbau principle, Pauli exclusion and Hund's rule, worked examples from hydrogen to iron, ions, noble gas shorthand, counting unpaired electrons, and common mistakes.
Orbital Box Diagram Practice Questions
Twelve orbital box diagram questions with full answers: filling boxes with Hund's rule and the Pauli principle, counting unpaired electrons, spotting errors, ions, and the chromium and copper exceptions.
Paper Chromatography: Method and Rf Values
A complete guide to paper chromatography: the principle of stationary and mobile phases, a step-by-step method, calculating Rf values, identifying substances, locating colourless spots, and evaluating results.
Paramagnetic vs Diamagnetic: Predicting Magnetism from Electrons
The difference between paramagnetic and diamagnetic substances, how unpaired electrons create magnetism, predicting magnetic behaviour from electron configurations of atoms, ions and molecules, ferromagnetism, the liquid oxygen demonstration, measuring magnetism, and practice questions.
The Pauli Exclusion Principle in Plain Language
What the Pauli exclusion principle says, why no two electrons in an atom can share all four quantum numbers, why each orbital holds only two electrons with opposite spins, how it produces shell capacities, the periodic table and the solidity of matter, and its role in white dwarfs and neutron stars.
Penicillin: Discovery and Chemistry
The story of penicillin from Alexander Fleming's contaminated plate in 1928 to Florey, Chain and Heatley's rescue of the idea, wartime mass production from a mouldy melon, Dorothy Hodgkin's structure of the β-lactam ring, and the chemistry that makes it work.
The Peptide Bond: How Amino Acids Link
How amino acids join by condensation to form peptide bonds, why the peptide bond is flat and rigid, resonance, the protein backbone, N- and C-termini, naming dipeptides, hydrolysis in digestion, and how chemists make peptides.
Percent Ionisation of Weak Acids
How to calculate the percentage of a weak acid that ionises, why dilution makes it rise, Ostwald's dilution law, and worked comparisons of acids like HF, methanoic and ethanoic acid.
Soil pH and Plant Growth
Why soil pH controls which nutrients plants can absorb, how acidic and alkaline soils form, which plants prefer each, how to test soil and how lime and sulfur change pH, with the chemistry behind hydrangea colours.
pH Calculations Practice Problems with Answers
20 pH practice problems in rising difficulty: strong acids, strong bases, [H⁺] from pH, masses, dilution, mixing, weak acids and temperature, each with full worked solutions.
Plotting a pH Curve with a pH Meter
A practical guide to recording a titration curve with a pH meter or data logger: method, a full sample data set for ethanoic acid, finding the equivalence point and pKa from the graph, derivative plots and evaluation.
How a pH Meter Works
Inside the glass electrode: how a thin glass membrane turns hydrogen ion concentration into a voltage, the Nernst equation's 59 mV per pH unit, reference electrodes, calibration, temperature compensation and care.
pH Inside the Body: Stomach, Blood, Skin and More
A tour of pH around the human body, from the stomach at pH 1.5 to pancreatic juice at 8, why each fluid has the pH it does, how the body controls it, and what happens when it goes wrong.
pH of Weak Acids: ICE Tables and Approximations
How to calculate the pH of a weak acid using Ka and an ICE table, when the square-root shortcut is safe, when you need the quadratic, and how to work backwards from pH to Ka.
pH of Weak Bases Using Kb
Calculate the pH of weak bases like ammonia, amines and anions using Kb, an ICE table and pOH, including when to use the quadratic and how to get Kb from Ka.
Sørensen and the Invention of the pH Scale
How a Danish chemist at a beer laboratory invented pH in 1909, why brewing needed it, what the 'p' stands for, and how pH moved from hydrogen ion concentration to activity and today's electrode measurements.
Phenolphthalein: Why It Turns Pink
The structure and chemistry of phenolphthalein: why it's colourless in acid and pink in alkali, why the pink fades in very strong alkali, its uses in titrations and forensics, and its history.
Phospholipids and Cell Membranes
How amphipathic phospholipids self-assemble into bilayers, the fluid mosaic model, membrane proteins, cholesterol's role, fluidity and temperature, what can cross a membrane and how, and how detergents and soaps disrupt membranes.
The Photoelectric Effect: The Experiment That Proved Light Comes in Packets
What the photoelectric effect is, the puzzling observations that classical wave theory couldn't explain, Einstein's 1905 photon explanation, threshold frequency and work function, why intensity changes the number but not the energy of electrons, Millikan's confirmation, and everyday uses from solar cells to night-vision.