# Periodic Table of Elements

> The free, citation-ready periodic table of elements — 118 guides, trends, calculators, and printable PDFs.

A multilingual interactive periodic table of the chemical elements with element detail pages, periodic trends, printable PDFs, isotope data, and cited scientific references.

## Elements

- [Elements](https://periodic-table-of-elements.top/fr/): Interactive periodic table with 8 property heatmaps, search, and learning entry points.
- [Tous les éléments](https://periodic-table-of-elements.top/fr/elements): Browse, filter, and search all 118 elements with detailed data.
- [Tendances périodiques](https://periodic-table-of-elements.top/fr/trends): How electronegativity, atomic radius, ionization energy, melting point, density, boiling point, atomic mass, and electron affinity vary across periods and down groups.
- [Tools](https://periodic-table-of-elements.top/fr/tools): Molar mass calculator, equation balancer, electron configuration tool, and element comparator.
- [Learn](https://periodic-table-of-elements.top/fr/learn): Articles explaining periodic table concepts, electron configuration, atomic mass, history, and how to memorize element symbols.
- [Tableaux périodiques à imprimer](https://periodic-table-of-elements.top/fr/printables): Download high-resolution PDFs and PNGs of the periodic table for study and classroom use.
- [Sources de données](https://periodic-table-of-elements.top/fr/data-sources): Authoritative references: IUPAC/CIAAW, PubChem, NIST, Bowserinator/Periodic-Table-JSON. Field-level units, ranges, and conflict resolution rules.

## Tous les éléments (118 total)

- [Hydrogen (H, 1)](https://periodic-table-of-elements.top/fr/elements/hydrogen): H, atomic number 1, atomic mass 1.008 u, reactive nonmetal.
- [Helium (He, 2)](https://periodic-table-of-elements.top/fr/elements/helium): He, atomic number 2, atomic mass 4.002602 u, noble gas.
- [Lithium (Li, 3)](https://periodic-table-of-elements.top/fr/elements/lithium): Li, atomic number 3, atomic mass 6.94 u, alkali metal.
- [Beryllium (Be, 4)](https://periodic-table-of-elements.top/fr/elements/beryllium): Be, atomic number 4, atomic mass 9.0121831 u, alkaline earth metal.
- [Boron (B, 5)](https://periodic-table-of-elements.top/fr/elements/boron): B, atomic number 5, atomic mass 10.81 u, metalloid.
- [Carbon (C, 6)](https://periodic-table-of-elements.top/fr/elements/carbon): C, atomic number 6, atomic mass 12.011 u, reactive nonmetal.
- [Nitrogen (N, 7)](https://periodic-table-of-elements.top/fr/elements/nitrogen): N, atomic number 7, atomic mass 14.007 u, reactive nonmetal.
- [Oxygen (O, 8)](https://periodic-table-of-elements.top/fr/elements/oxygen): O, atomic number 8, atomic mass 15.999 u, reactive nonmetal.
- [Fluorine (F, 9)](https://periodic-table-of-elements.top/fr/elements/fluorine): F, atomic number 9, atomic mass 18.998403162 u, reactive nonmetal.
- [Neon (Ne, 10)](https://periodic-table-of-elements.top/fr/elements/neon): Ne, atomic number 10, atomic mass 20.1797 u, noble gas.
- [Sodium (Na, 11)](https://periodic-table-of-elements.top/fr/elements/sodium): Na, atomic number 11, atomic mass 22.98976928 u, alkali metal.
- [Magnesium (Mg, 12)](https://periodic-table-of-elements.top/fr/elements/magnesium): Mg, atomic number 12, atomic mass 24.305 u, alkaline earth metal.
- [Aluminum (Al, 13)](https://periodic-table-of-elements.top/fr/elements/aluminum): Al, atomic number 13, atomic mass 26.9815384 u, post-transition metal.
- [Silicon (Si, 14)](https://periodic-table-of-elements.top/fr/elements/silicon): Si, atomic number 14, atomic mass 28.085 u, metalloid.
- [Phosphorus (P, 15)](https://periodic-table-of-elements.top/fr/elements/phosphorus): P, atomic number 15, atomic mass 30.973761998 u, reactive nonmetal.
- [Sulfur (S, 16)](https://periodic-table-of-elements.top/fr/elements/sulfur): S, atomic number 16, atomic mass 32.06 u, reactive nonmetal.
- [Chlorine (Cl, 17)](https://periodic-table-of-elements.top/fr/elements/chlorine): Cl, atomic number 17, atomic mass 35.45 u, reactive nonmetal.
- [Argon (Ar, 18)](https://periodic-table-of-elements.top/fr/elements/argon): Ar, atomic number 18, atomic mass 39.948 u, noble gas.
- [Potassium (K, 19)](https://periodic-table-of-elements.top/fr/elements/potassium): K, atomic number 19, atomic mass 39.0983 u, alkali metal.
- [Calcium (Ca, 20)](https://periodic-table-of-elements.top/fr/elements/calcium): Ca, atomic number 20, atomic mass 40.078 u, alkaline earth metal.
- [Scandium (Sc, 21)](https://periodic-table-of-elements.top/fr/elements/scandium): Sc, atomic number 21, atomic mass 44.955907 u, transition metal.
- [Titanium (Ti, 22)](https://periodic-table-of-elements.top/fr/elements/titanium): Ti, atomic number 22, atomic mass 47.867 u, transition metal.
- [Vanadium (V, 23)](https://periodic-table-of-elements.top/fr/elements/vanadium): V, atomic number 23, atomic mass 50.9415 u, transition metal.
- [Chromium (Cr, 24)](https://periodic-table-of-elements.top/fr/elements/chromium): Cr, atomic number 24, atomic mass 51.9961 u, transition metal.
- [Manganese (Mn, 25)](https://periodic-table-of-elements.top/fr/elements/manganese): Mn, atomic number 25, atomic mass 54.938043 u, transition metal.
- [Iron (Fe, 26)](https://periodic-table-of-elements.top/fr/elements/iron): Fe, atomic number 26, atomic mass 55.845 u, transition metal.
- [Cobalt (Co, 27)](https://periodic-table-of-elements.top/fr/elements/cobalt): Co, atomic number 27, atomic mass 58.933194 u, transition metal.
- [Nickel (Ni, 28)](https://periodic-table-of-elements.top/fr/elements/nickel): Ni, atomic number 28, atomic mass 58.6934 u, transition metal.
- [Copper (Cu, 29)](https://periodic-table-of-elements.top/fr/elements/copper): Cu, atomic number 29, atomic mass 63.546 u, transition metal.
- [Zinc (Zn, 30)](https://periodic-table-of-elements.top/fr/elements/zinc): Zn, atomic number 30, atomic mass 65.38 u, transition metal.
- [Gallium (Ga, 31)](https://periodic-table-of-elements.top/fr/elements/gallium): Ga, atomic number 31, atomic mass 69.723 u, post-transition metal.
- [Germanium (Ge, 32)](https://periodic-table-of-elements.top/fr/elements/germanium): Ge, atomic number 32, atomic mass 72.63 u, metalloid.
- [Arsenic (As, 33)](https://periodic-table-of-elements.top/fr/elements/arsenic): As, atomic number 33, atomic mass 74.921595 u, metalloid.
- [Selenium (Se, 34)](https://periodic-table-of-elements.top/fr/elements/selenium): Se, atomic number 34, atomic mass 78.971 u, reactive nonmetal.
- [Bromine (Br, 35)](https://periodic-table-of-elements.top/fr/elements/bromine): Br, atomic number 35, atomic mass 79.904 u, reactive nonmetal.
- [Krypton (Kr, 36)](https://periodic-table-of-elements.top/fr/elements/krypton): Kr, atomic number 36, atomic mass 83.798 u, noble gas.
- [Rubidium (Rb, 37)](https://periodic-table-of-elements.top/fr/elements/rubidium): Rb, atomic number 37, atomic mass 85.4678 u, alkali metal.
- [Strontium (Sr, 38)](https://periodic-table-of-elements.top/fr/elements/strontium): Sr, atomic number 38, atomic mass 87.62 u, alkaline earth metal.
- [Yttrium (Y, 39)](https://periodic-table-of-elements.top/fr/elements/yttrium): Y, atomic number 39, atomic mass 88.905838 u, transition metal.
- [Zirconium (Zr, 40)](https://periodic-table-of-elements.top/fr/elements/zirconium): Zr, atomic number 40, atomic mass 91.224 u, transition metal.
- [Niobium (Nb, 41)](https://periodic-table-of-elements.top/fr/elements/niobium): Nb, atomic number 41, atomic mass 92.90637 u, transition metal.
- [Molybdenum (Mo, 42)](https://periodic-table-of-elements.top/fr/elements/molybdenum): Mo, atomic number 42, atomic mass 95.95 u, transition metal.
- [Technetium (Tc, 43)](https://periodic-table-of-elements.top/fr/elements/technetium): Tc, atomic number 43, atomic mass 98 u, transition metal.
- [Ruthenium (Ru, 44)](https://periodic-table-of-elements.top/fr/elements/ruthenium): Ru, atomic number 44, atomic mass 101.07 u, transition metal.
- [Rhodium (Rh, 45)](https://periodic-table-of-elements.top/fr/elements/rhodium): Rh, atomic number 45, atomic mass 102.90549 u, transition metal.
- [Palladium (Pd, 46)](https://periodic-table-of-elements.top/fr/elements/palladium): Pd, atomic number 46, atomic mass 106.42 u, transition metal.
- [Silver (Ag, 47)](https://periodic-table-of-elements.top/fr/elements/silver): Ag, atomic number 47, atomic mass 107.8682 u, transition metal.
- [Cadmium (Cd, 48)](https://periodic-table-of-elements.top/fr/elements/cadmium): Cd, atomic number 48, atomic mass 112.414 u, transition metal.
- [Indium (In, 49)](https://periodic-table-of-elements.top/fr/elements/indium): In, atomic number 49, atomic mass 114.818 u, post-transition metal.
- [Tin (Sn, 50)](https://periodic-table-of-elements.top/fr/elements/tin): Sn, atomic number 50, atomic mass 118.710 u, post-transition metal.
- [Antimony (Sb, 51)](https://periodic-table-of-elements.top/fr/elements/antimony): Sb, atomic number 51, atomic mass 121.760 u, metalloid.
- [Tellurium (Te, 52)](https://periodic-table-of-elements.top/fr/elements/tellurium): Te, atomic number 52, atomic mass 127.60 u, metalloid.
- [Iodine (I, 53)](https://periodic-table-of-elements.top/fr/elements/iodine): I, atomic number 53, atomic mass 126.90447 u, reactive nonmetal.
- [Xenon (Xe, 54)](https://periodic-table-of-elements.top/fr/elements/xenon): Xe, atomic number 54, atomic mass 131.293 u, noble gas.
- [Cesium (Cs, 55)](https://periodic-table-of-elements.top/fr/elements/cesium): Cs, atomic number 55, atomic mass 132.90545196 u, alkali metal.
- [Barium (Ba, 56)](https://periodic-table-of-elements.top/fr/elements/barium): Ba, atomic number 56, atomic mass 137.327 u, alkaline earth metal.
- [Lanthanum (La, 57)](https://periodic-table-of-elements.top/fr/elements/lanthanum): La, atomic number 57, atomic mass 138.90547 u, lanthanide.
- [Cerium (Ce, 58)](https://periodic-table-of-elements.top/fr/elements/cerium): Ce, atomic number 58, atomic mass 140.116 u, lanthanide.
- [Praseodymium (Pr, 59)](https://periodic-table-of-elements.top/fr/elements/praseodymium): Pr, atomic number 59, atomic mass 140.90766 u, lanthanide.
- [Neodymium (Nd, 60)](https://periodic-table-of-elements.top/fr/elements/neodymium): Nd, atomic number 60, atomic mass 144.242 u, lanthanide.
- [Promethium (Pm, 61)](https://periodic-table-of-elements.top/fr/elements/promethium): Pm, atomic number 61, atomic mass 145 u, lanthanide.
- [Samarium (Sm, 62)](https://periodic-table-of-elements.top/fr/elements/samarium): Sm, atomic number 62, atomic mass 150.36 u, lanthanide.
- [Europium (Eu, 63)](https://periodic-table-of-elements.top/fr/elements/europium): Eu, atomic number 63, atomic mass 151.964 u, lanthanide.
- [Gadolinium (Gd, 64)](https://periodic-table-of-elements.top/fr/elements/gadolinium): Gd, atomic number 64, atomic mass 157.25 u, lanthanide.
- [Terbium (Tb, 65)](https://periodic-table-of-elements.top/fr/elements/terbium): Tb, atomic number 65, atomic mass 158.925354 u, lanthanide.
- [Dysprosium (Dy, 66)](https://periodic-table-of-elements.top/fr/elements/dysprosium): Dy, atomic number 66, atomic mass 162.500 u, lanthanide.
- [Holmium (Ho, 67)](https://periodic-table-of-elements.top/fr/elements/holmium): Ho, atomic number 67, atomic mass 164.930329 u, lanthanide.
- [Erbium (Er, 68)](https://periodic-table-of-elements.top/fr/elements/erbium): Er, atomic number 68, atomic mass 167.259 u, lanthanide.
- [Thulium (Tm, 69)](https://periodic-table-of-elements.top/fr/elements/thulium): Tm, atomic number 69, atomic mass 168.934219 u, lanthanide.
- [Ytterbium (Yb, 70)](https://periodic-table-of-elements.top/fr/elements/ytterbium): Yb, atomic number 70, atomic mass 173.045 u, lanthanide.
- [Lutetium (Lu, 71)](https://periodic-table-of-elements.top/fr/elements/lutetium): Lu, atomic number 71, atomic mass 174.9668 u, lanthanide.
- [Hafnium (Hf, 72)](https://periodic-table-of-elements.top/fr/elements/hafnium): Hf, atomic number 72, atomic mass 178.486 u, transition metal.
- [Tantalum (Ta, 73)](https://periodic-table-of-elements.top/fr/elements/tantalum): Ta, atomic number 73, atomic mass 180.94788 u, transition metal.
- [Tungsten (W, 74)](https://periodic-table-of-elements.top/fr/elements/tungsten): W, atomic number 74, atomic mass 183.84 u, transition metal.
- [Rhenium (Re, 75)](https://periodic-table-of-elements.top/fr/elements/rhenium): Re, atomic number 75, atomic mass 186.207 u, transition metal.
- [Osmium (Os, 76)](https://periodic-table-of-elements.top/fr/elements/osmium): Os, atomic number 76, atomic mass 190.23 u, transition metal.
- [Iridium (Ir, 77)](https://periodic-table-of-elements.top/fr/elements/iridium): Ir, atomic number 77, atomic mass 192.217 u, transition metal.
- [Platinum (Pt, 78)](https://periodic-table-of-elements.top/fr/elements/platinum): Pt, atomic number 78, atomic mass 195.084 u, transition metal.
- [Gold (Au, 79)](https://periodic-table-of-elements.top/fr/elements/gold): Au, atomic number 79, atomic mass 196.966570 u, transition metal.
- [Mercury (Hg, 80)](https://periodic-table-of-elements.top/fr/elements/mercury): Hg, atomic number 80, atomic mass 200.59 u, transition metal.
- [Thallium (Tl, 81)](https://periodic-table-of-elements.top/fr/elements/thallium): Tl, atomic number 81, atomic mass 204.38 u, post-transition metal.
- [Lead (Pb, 82)](https://periodic-table-of-elements.top/fr/elements/lead): Pb, atomic number 82, atomic mass 207.2 u, post-transition metal.
- [Bismuth (Bi, 83)](https://periodic-table-of-elements.top/fr/elements/bismuth): Bi, atomic number 83, atomic mass 208.98040 u, post-transition metal.
- [Polonium (Po, 84)](https://periodic-table-of-elements.top/fr/elements/polonium): Po, atomic number 84, atomic mass 209 u, post-transition metal.
- [Astatine (At, 85)](https://periodic-table-of-elements.top/fr/elements/astatine): At, atomic number 85, atomic mass 210 u, metalloid.
- [Radon (Rn, 86)](https://periodic-table-of-elements.top/fr/elements/radon): Rn, atomic number 86, atomic mass 222 u, noble gas.
- [Francium (Fr, 87)](https://periodic-table-of-elements.top/fr/elements/francium): Fr, atomic number 87, atomic mass 223 u, alkali metal.
- [Radium (Ra, 88)](https://periodic-table-of-elements.top/fr/elements/radium): Ra, atomic number 88, atomic mass 226 u, alkaline earth metal.
- [Actinium (Ac, 89)](https://periodic-table-of-elements.top/fr/elements/actinium): Ac, atomic number 89, atomic mass 227 u, actinide.
- [Thorium (Th, 90)](https://periodic-table-of-elements.top/fr/elements/thorium): Th, atomic number 90, atomic mass 232.0377 u, actinide.
- [Protactinium (Pa, 91)](https://periodic-table-of-elements.top/fr/elements/protactinium): Pa, atomic number 91, atomic mass 231.03588 u, actinide.
- [Uranium (U, 92)](https://periodic-table-of-elements.top/fr/elements/uranium): U, atomic number 92, atomic mass 238.02891 u, actinide.
- [Neptunium (Np, 93)](https://periodic-table-of-elements.top/fr/elements/neptunium): Np, atomic number 93, atomic mass 237 u, actinide.
- [Plutonium (Pu, 94)](https://periodic-table-of-elements.top/fr/elements/plutonium): Pu, atomic number 94, atomic mass 244 u, actinide.
- [Americium (Am, 95)](https://periodic-table-of-elements.top/fr/elements/americium): Am, atomic number 95, atomic mass 243 u, actinide.
- [Curium (Cm, 96)](https://periodic-table-of-elements.top/fr/elements/curium): Cm, atomic number 96, atomic mass 247 u, actinide.
- [Berkelium (Bk, 97)](https://periodic-table-of-elements.top/fr/elements/berkelium): Bk, atomic number 97, atomic mass 247 u, actinide.
- [Californium (Cf, 98)](https://periodic-table-of-elements.top/fr/elements/californium): Cf, atomic number 98, atomic mass 251 u, actinide.
- [Einsteinium (Es, 99)](https://periodic-table-of-elements.top/fr/elements/einsteinium): Es, atomic number 99, atomic mass 252 u, actinide.
- [Fermium (Fm, 100)](https://periodic-table-of-elements.top/fr/elements/fermium): Fm, atomic number 100, atomic mass 257 u, actinide.
- [Mendelevium (Md, 101)](https://periodic-table-of-elements.top/fr/elements/mendelevium): Md, atomic number 101, atomic mass 258 u, actinide.
- [Nobelium (No, 102)](https://periodic-table-of-elements.top/fr/elements/nobelium): No, atomic number 102, atomic mass 259 u, actinide.
- [Lawrencium (Lr, 103)](https://periodic-table-of-elements.top/fr/elements/lawrencium): Lr, atomic number 103, atomic mass 266 u, actinide.
- [Rutherfordium (Rf, 104)](https://periodic-table-of-elements.top/fr/elements/rutherfordium): Rf, atomic number 104, atomic mass 267 u, transition metal.
- [Dubnium (Db, 105)](https://periodic-table-of-elements.top/fr/elements/dubnium): Db, atomic number 105, atomic mass 268 u, transition metal.
- [Seaborgium (Sg, 106)](https://periodic-table-of-elements.top/fr/elements/seaborgium): Sg, atomic number 106, atomic mass 269 u, transition metal.
- [Bohrium (Bh, 107)](https://periodic-table-of-elements.top/fr/elements/bohrium): Bh, atomic number 107, atomic mass 270 u, transition metal.
- [Hassium (Hs, 108)](https://periodic-table-of-elements.top/fr/elements/hassium): Hs, atomic number 108, atomic mass 270 u, transition metal.
- [Meitnerium (Mt, 109)](https://periodic-table-of-elements.top/fr/elements/meitnerium): Mt, atomic number 109, atomic mass 278 u, unknown.
- [Darmstadtium (Ds, 110)](https://periodic-table-of-elements.top/fr/elements/darmstadtium): Ds, atomic number 110, atomic mass 281 u, unknown.
- [Roentgenium (Rg, 111)](https://periodic-table-of-elements.top/fr/elements/roentgenium): Rg, atomic number 111, atomic mass 282 u, unknown.
- [Copernicium (Cn, 112)](https://periodic-table-of-elements.top/fr/elements/copernicium): Cn, atomic number 112, atomic mass 285 u, unknown.
- [Nihonium (Nh, 113)](https://periodic-table-of-elements.top/fr/elements/nihonium): Nh, atomic number 113, atomic mass 286 u, unknown.
- [Flerovium (Fl, 114)](https://periodic-table-of-elements.top/fr/elements/flerovium): Fl, atomic number 114, atomic mass 289 u, unknown.
- [Moscovium (Mc, 115)](https://periodic-table-of-elements.top/fr/elements/moscovium): Mc, atomic number 115, atomic mass 290 u, unknown.
- [Livermorium (Lv, 116)](https://periodic-table-of-elements.top/fr/elements/livermorium): Lv, atomic number 116, atomic mass 293 u, unknown.
- [Tennessine (Ts, 117)](https://periodic-table-of-elements.top/fr/elements/tennessine): Ts, atomic number 117, atomic mass 294 u, unknown.
- [Oganesson (Og, 118)](https://periodic-table-of-elements.top/fr/elements/oganesson): Og, atomic number 118, atomic mass 294 u, unknown.

## Tendances périodiques

- [Electronegativity](https://periodic-table-of-elements.top/fr/trends/electronegativity): A measure of the tendency of an atom to attract a bonding pair of electrons. (unit: Pauling).
- [Atomic Radius](https://periodic-table-of-elements.top/fr/trends/atomic_radius): The distance from the center of the nucleus to the boundary of the surrounding cloud of electrons. (unit: pm).
- [Ionization Energy](https://periodic-table-of-elements.top/fr/trends/ionization_energy): The energy required to remove the most loosely bound electron from a neutral gaseous atom. (unit: kJ/mol).
- [Melting Point](https://periodic-table-of-elements.top/fr/trends/melting_point): The temperature at which the solid phase of a pure substance is in equilibrium with its liquid phase at atmospheric pressure. (unit: K).
- [Density at STP](https://periodic-table-of-elements.top/fr/trends/density_stp): Mass per unit volume of a substance at standard temperature and pressure. (unit: g/cm3).
- [Boiling Point](https://periodic-table-of-elements.top/fr/trends/boiling_point): The temperature at which the vapor pressure of a liquid equals the external atmospheric pressure. (unit: K).
- [Atomic Mass](https://periodic-table-of-elements.top/fr/trends/atomic_mass): The mass of an atom, typically expressed in unified atomic mass units. (unit: u).
- [Electron Affinity](https://periodic-table-of-elements.top/fr/trends/electron_affinity): The amount of energy released when an electron is added to a neutral atom in the gaseous state. (unit: kJ/mol).
- [Thermal Conductivity](https://periodic-table-of-elements.top/fr/trends/thermal_conductivity): Rate at which heat flows through a material. Metals conduct heat well; gases and nonmetals poorly. (unit: W/(m·K)).
- [Crustal Abundance](https://periodic-table-of-elements.top/fr/trends/abundance_crust): How much of the element is found in the Earth's crust, measured in milligrams per kilogram of crustal rock. (unit: mg/kg).
- [Oxidation States](https://periodic-table-of-elements.top/fr/trends/oxidation_states): Number of distinct oxidation states the element commonly exhibits in compounds. (unit: count).

## Tableaux périodiques à imprimer

- [Periodic Table (Color)](https://periodic-table-of-elements.top/fr/printables#periodic-table-color): Full-color A4 / Letter PDF, all 118 elements with categories.
- [Periodic Table (Wide)](https://periodic-table-of-elements.top/fr/printables#periodic-table-wide): Wide-format PDF for landscape printing across two pages.
- [Elements Poster 1](https://periodic-table-of-elements.top/fr/printables#pdf-1): High-resolution PNG poster of element symbols and atomic numbers.
- [Elements Poster 2](https://periodic-table-of-elements.top/fr/printables#pdf-2): High-resolution PNG poster with category colors.
- [Elements Poster 3](https://periodic-table-of-elements.top/fr/printables#pdf-3): High-resolution PNG poster with discovery year.
- [Elements Poster 4](https://periodic-table-of-elements.top/fr/printables#pdf-4): High-resolution PNG poster with electron configuration.

## Tools

- [Molar Mass Calculator](https://periodic-table-of-elements.top/fr/tools/molar-mass-calculator): Compute molecular weight from chemical formulas; supports hydrates (·nH2O), nested brackets, square-bracket complexes, and standalone ion notation.
- [Equation Balancer](https://periodic-table-of-elements.top/fr/tools/balance-equation): Balance chemical equations with arbitrary reactants and products using an integer-LCM algorithm; rejects unbalanceable inputs.
- [Electron Configuration Calculator](https://periodic-table-of-elements.top/fr/tools/electron-configuration-calculator): Full and shorthand electron configuration for any of the 118 elements with orbital diagrams and 13 documented anomalous ground states (Cr, Cu, Mo, Pd, Au, La, Gd, ...).
- [Element Comparator](https://periodic-table-of-elements.top/fr/tools/compare-elements): Side-by-side comparison of any subset of the 118 elements across atomic, thermodynamic, electrical, and abundance properties.

## Quizzes

- [Element Symbol Quiz](https://periodic-table-of-elements.top/fr/quizzes/element-symbol-quiz): Multiple-choice drills matching element names to symbols. Three difficulty levels; tracks the last 10 attempts in localStorage.
- [Atomic Number Quiz](https://periodic-table-of-elements.top/fr/quizzes/atomic-number-quiz): Identify an element from its atomic number and a clue. Three difficulty levels; recent-attempts history is preserved locally.
- [Category Quiz](https://periodic-table-of-elements.top/fr/quizzes/category-quiz): Place elements into their periodic-table category (alkali metal, transition metal, noble gas, ...). Three difficulty levels.
- [Electron Configuration Quiz](https://periodic-table-of-elements.top/fr/quizzes/electron-config-quiz): Identify elements from a partial electron configuration clue. Three difficulty levels.

## Learn

- [Comment lire le tableau périodique : guide du débutant](https://periodic-table-of-elements.top/fr/learn/how-to-read-the-periodic-table): Une présentation pratique de chaque partie d'une cellule du tableau périodique — numéro atomique, symbole, masse atomique, groupe, période, bloc, catégorie — avec des exemples allant de l'hydrogène à l'oganesson.
- [Comment mémoriser le tableau périodique : symboles, nombres et catégories](https://periodic-table-of-elements.top/fr/learn/how-to-memorize-element-symbols): Stratégies mnémoniques éprouvées pour apprendre les symboles des éléments et les numéros atomiques sans mémorisation par force brute. Répétition espacée, découpage et reconnaissance de formes.
- [Configuration électronique expliquée : Aufbau, couches et sténographie](https://periodic-table-of-elements.top/fr/learn/electron-configuration-explained): Une présentation claire de la notation de la configuration électronique, de l'ordre de remplissage d'Aufbau, des coquilles et des sous-couches et de la façon de lire la configuration de n'importe quel élément, de l'hydrogène à l'oganesson.
- [Les groupes du tableau périodique expliqués : les 18 colonnes et leur chimie](https://periodic-table-of-elements.top/fr/learn/periodic-table-groups-explained): Ce que signifient les 18 groupes (colonnes) du tableau périodique, pourquoi les éléments d'un même groupe se comportent de la même manière et le modèle unique qui vous permet de prédire la chimie.
- [Masse atomique vs nombre de masse : quelle est la différence ?](https://periodic-table-of-elements.top/fr/learn/atomic-mass-vs-mass-number): Le nombre de masse compte les nucléons individuels ; la masse atomique est une moyenne pondérée de tous les isotopes. Ce guide passe en revue les deux, montre comment ils apparaissent dans le tableau périodique et explique la notation entre parenthèses pour les éléments instables.
- [Périodes du tableau périodique expliquées : les 7 lignes et leurs modèles](https://periodic-table-of-elements.top/fr/learn/periodic-table-periods-explained): Comment les 7 lignes horizontales (périodes) du tableau périodique codent le nombre de couches électroniques et les ondes chimiques prévisibles qui se répètent à chaque période.
- [Pourquoi les éléments ont des propriétés différentes : la loi périodique](https://periodic-table-of-elements.top/fr/learn/why-elements-have-different-properties): Différents éléments sont différents en raison de leurs configurations électroniques. Ce guide relie le nombre de protons au nombre d'électrons, à la couche de valence et à la chimie, avec des exemples concrets tirés du tableau périodique.
- [Que sont les isotopes ? Définition, exemples et pourquoi ils sont importants](https://periodic-table-of-elements.top/fr/learn/what-are-isotopes): Une explication simple des isotopes, de la notation isotopique, de la stabilité, de la demi-vie et du rôle que jouent les isotopes en médecine, en archéologie et en énergie nucléaire.
- [Une brève histoire du tableau périodique : des triades à Oganesson](https://periodic-table-of-elements.top/fr/learn/periodic-table-history): Comment les chimistes du XIXe siècle ont remarqué des motifs répétitifs dans les éléments, les ont organisés en tableaux toujours meilleurs, ont prédit les éléments manquants et sont arrivés au tableau de 118 éléments que nous utilisons aujourd'hui.

## Optional

- [Sources de données](https://periodic-table-of-elements.top/fr/data-sources): IUPAC, PubChem, NIST references and conflict resolution rules.
- [Full structured dump](https://periodic-table-of-elements.top/fr/llms-full.txt): per-element markdown with all numeric fields.