Periodic Table FAQ

A1: A free page with the periodic table of all 118 elements and five tabs: Table (search, colour by a property, heat the table, rewind history), Trends (charts across the elements), Compare (up to four elements side by side), Lab (molar mass, empirical formulas, an equation balancer and molecules in 3D) and Quiz.

A2: It is free and there is no account or registration. Like every page on ZeroDataUpload, it is supported by advertising.

A3: No. The search, the charts and every calculation run in your browser. The page itself, its ads and its analytics load from the internet as on any website, but the formulas, equations and answers you type are never sent with them.

A4: Your settings (colour by, temperature and unit, table or list, the elements in Compare, the chart choices, the model style) and your best quiz scores, under this tool's own name. Nothing is kept until you change one of them; looking around writes nothing.

A5: Current versions of Chrome, Edge, Firefox and Safari on computers and phones. The 3D molecules need a browser that can draw on a canvas, which all current browsers can.

A6: Yes. The arrow keys move between the tabs and around the table, Enter opens an element, the left and right arrows step through elements in the element window, / jumps to the search while you use the tool, 1 to 4 answer a quiz question, and Escape closes a window.

A7: The coloured edge shows the family, such as alkali metals or noble gases. The fill shows the state at the temperature you choose: full for a solid, half for a liquid, empty with a dashed edge for a gas, and a hatched square where the state is not known.

A8: It runs from absolute zero (0 K) to 6000 K, past the surface of the Sun. Each element is solid below its melting point, liquid up to its boiling point and a gas above it, at normal atmospheric pressure. Presets jump to liquid nitrogen, room temperature, boiling water, lava and the Sun's surface.

A9: At normal pressure they do not melt: the solid turns straight to gas, which is called sublimation. Carbon does so at about 3825 °C and grey arsenic at about 616 °C. Both melt only under high pressure.

A10: Helium is the one element that never freezes at normal pressure. It becomes solid only when squeezed to about 25 times atmospheric pressure, so the table shows it as a liquid below 4.2 K (about minus 269 °C) and a gas above.

A11: With colour by a property, a hatched square has no measured value. With colour by family, a hatched square means the state is unknown at that temperature: its melting point has never been measured, or it has melted and its boiling point is not known.

A12: It fades out the elements not yet discovered in the chosen year, from 1640 to today. Replay history runs through the years in about 16 seconds and names each year's discoveries.

A13: A name (aluminium or aluminum, sulfur or sulphur, caesium or cesium, wolfram), a symbol, an atomic number, a family (halogens, noble gases, metals, nonmetals, rare earths), "group 14", "period 4", "d-block", "solid", "liquid", "gas", "radioactive" or "synthetic".

A14: Yes. Choose List to see every element as a row with its family, atomic weight, state, electronegativity, ionisation energy, covalent radius, density, melting and boiling points and year of discovery. Choose a column heading to sort.

A15: Standard atomic weights: IUPAC's Commission on Isotopic Abundances and Atomic Weights (CIAAW), 2024, in their five-figure form. Melting and boiling points, densities, Pauling electronegativity, electron affinity and abundance in the Earth's crust: the CRC Handbook of Chemistry and Physics, taken from the open mendeleev data set. Ionisation energies: the NIST Atomic Spectra Database. Covalent radii: Cordero and others (2008). Atomic radii: Rahm, Hoffmann and Ashcroft (2016 and 2017).

A16: Radioactive elements have no standard atomic weight. The number in square brackets is the mass number of the longest-lived isotope, from CIAAW's list, which is based on the NUBASE2020 evaluation of nuclear data. Where that list names two isotopes, the table shows one of them.

A17: Only a few atoms of them have ever been made, often for less than a second. Their melting points, densities and much of their chemistry have never been measured, so the table shows them as unknown instead of showing predictions as if they were measurements. Their electron configurations, marked as predictions, are the exception.

A18: How strongly an atom pulls shared electrons towards itself in a bond, on Linus Pauling's scale: fluorine is highest at 3.98 and caesium among the lowest. The noble gases helium, neon and argon have no value on this scale.

A19: A year of discovery can mean when an element was first recognised or when it was first isolated. This table follows PubChem's periodic table or Wikidata wherever either agrees, the Nobel Prize citation for fluorine (isolated by Henri Moissan in 1886), and the IUPAC and IUPAP working group's 1993 verdicts for elements 102, 105 and 107.

A20: Each bar shows where the value sits among all elements, from the lowest to the highest, so a short bar means low for the whole table, not just among the elements you picked. Abundance uses a scale in powers of ten.

A21: Open Lab, Molar mass, and type a formula such as H2SO4, Ca(OH)2 or CuSO4.5H2O. The tool shows the molar mass in g/mol, the number of atoms, the formula in Hill order and the share of the mass of each element, and converts between grams, moles and formula units.

A22: Because symbols do: Co is cobalt, CO is carbon monoxide. Each symbol starts with a capital letter. If you type a symbol in small letters, the tool suggests the capitalised version.

A23: Enter the mass percentage of each element from an analysis. The tool divides each by its atomic weight, divides by the smallest and finds the smallest whole-number ratio. If you add the molar mass, it also gives the molecular formula, a whole multiple of the empirical one. Try vitamin C shows an example.

A24: Open Lab, Balance, and type the substances with + between them and = or -> between the two sides, for example C6H12O6 + O2 = CO2 + H2O. Ions are written with ^, such as Fe^3+ or MnO4^-, and an electron as e^-. The result shows the smallest whole numbers and a table checking every atom and the charge.

A25: Either an element appears on only one side, no set of positive whole numbers works (a substance may be on the wrong side), or the equation can balance in more than one way because it is two reactions written as one. The message says which.

A26: 23 models in three groups: everyday molecules such as water, carbon dioxide, ethanol and benzene; the VSEPR shapes from linear to octahedral, with lone pairs drawn as faint clouds; and three structures: a salt crystal, diamond and buckminsterfullerene. Drag to turn, scroll or pinch to zoom, and switch between ball and stick and space filling.

A27: Find it (choose the right square on a blank table), Name it (pick the element from its symbol), Symbol (pick the symbol for a name) and Family, each ten questions over the first 20, 54 or all 118 elements, and All 118, where you type every element's name from memory against the clock.

A28: Your best score for each kind of round and pool, and your best time for All 118, are kept in this browser on this device.

A29: Yes. Copy link in an element's window, under a comparison, under a molar mass or under a balanced equation copies a link that opens the tool on the same thing. The link holds only the element, the list of elements or the formula; the tool reads it when the page opens and then takes it out of the address.

A30: It is the site's only periodic table and chemistry tool. The site's unit converter turns temperatures and other units into each other; this tool shows what those temperatures mean for every element and works out chemistry with the element data.