This interactive periodic table shows all 118 chemical elements. Tap any tile to see a spinning 3D model of its atom and its main properties. Recolour the table to reveal trends, heat it up to watch elements melt and boil, or start the quiz to test what you know.
How to use this interactive periodic table
Tap or click any tile to open its card. The card shows a spinning model of the atom, its electrons per shell, its valence electrons and its main properties. The toolbar above the table changes every tile at once, so you can see patterns across all 118 elements instead of reading them one at a time.
- Find an element takes a name, symbol or atomic number and makes the matching tiles glow.
- Colour by repaints the table by one property, such as Atom size, Pull on electrons or Melting point. Hatched tiles have no data.
- Temperature runs from 0 to 6000 kelvin; tiles switch between solid, liquid and gas as you drag. Room temperature resets it to 298 K (25 °C, 77 °F).
- 3D view raises each tile by its value in the current mode, which turns the table into a bar chart. Drag to tilt it.
- Quiz me asks 10 questions in three styles: Find it, What's the symbol? and What type is it? Choose the first 20 elements, the first 36 or all 118.
- On a phone the table scrolls sideways. Fit whole table shrinks it to your screen.
Every tile is a link, so ?el=Hg opens the page with mercury selected. The card also links to the atom 3D model for a larger view of the same atom.
What is the periodic table?
The periodic table is a chart of every known chemical element, arranged by atomic number. The atomic number is the number of protons in an atom's nucleus. Elements in the same column behave in similar ways, so the table works as a map of how matter reacts. IUPAC, the body that names elements, recognizes 118.
Dmitri Mendeleev published the first widely used version in 1869, with the elements ordered by atomic weight. In 1913 Henry Moseley showed that the true order is atomic number. That explained why Mendeleev had been right to put tellurium before iodine, though tellurium is heavier.
Atoms of one element can differ in their number of neutrons. These variants are isotopes. See the complete list of isotopes or examples of isotopes.
How is the periodic table organized?
The periodic table is organized into 7 rows called periods and 18 columns called groups. Atomic number rises by one from each tile to the next, left to right and top to bottom. A new period starts each time atoms begin filling a new electron shell. Elements in the same group have the same number of outer electrons.
- Periods are the rows. The period number matches the number of electron shells, with palladium the one exception. Sodium is in period 3 and has 3 shells.
- Groups are the columns. Group 1 holds the alkali metals, group 17 the halogens and group 18 the noble gases.
- Blocks are named after the orbital the outermost electrons are filling: s (groups 1 and 2 plus helium), d (groups 3 to 12), p (groups 13 to 18) and f (the two bottom rows).
An s orbital set holds 2 electrons, p holds 6, d holds 10 and f holds 14, which sets the width of each block. Pick s/p/d/f block in Colour by to see them.
What do the colours mean?
In the default view, colour shows the element type. Each colour marks a family of elements that behave alike, such as the alkali metals or the noble gases. When you switch Colour by to a property, the colours become a scale from low to high, and the legend above the table shows the values at each end.
- Alkali metals (group 1, without hydrogen) are soft and react with water. Alkaline earth metals (group 2) react less strongly.
- Transition metals such as iron fill the middle. Post-transition metals such as lead are softer. Metalloids such as silicon sit between metals and nonmetals.
- Other nonmetals include hydrogen, carbon and oxygen. Halogens (group 17) form salts with metals. Noble gases (group 18) barely react.
- Lanthanides and Actinides fill the two bottom rows. Unknown properties marks superheavy elements made only a few atoms at a time.
Periodic trends explained
Periodic trends are patterns that repeat in every period. Atoms get bigger going down a group and generally smaller going across a period. The pull on electrons and the energy needed to remove one both rise toward the top right of the table. Two things drive all three trends: the charge of the nucleus and the number of shells.
Atom size. Each period down a group adds a shell, so lithium measures 182 pm (picometres) and cesium 343 pm. Across a period, each step adds a proton but no new shell, so the nucleus pulls the electrons in: sodium measures 227 pm and chlorine, at the other end of period 3, 175 pm. The tool shows van der Waals radii, so a few tiles break the pattern.
Pull on electrons (electronegativity). How strongly an atom pulls the electrons it shares in a bond, on the Pauling scale. Small atoms with a nearly full outer shell pull hardest. Fluorine is highest at 3.98 and francium lowest at 0.7. Helium, neon and argon show No data because they almost never form bonds.
Energy to remove an electron (ionization energy). The energy needed to pull off the outermost electron, in electronvolts (eV). Helium holds on hardest at 24.59 eV. Cesium lets go most easily at 3.89 eV, because its one outer electron sits far out, behind 5 full shells. That is why the alkali metals react so fast.
Trends also predict ion charges: group 1 metals form +1 ions and halogens form -1 ions. Practise ions with the polyatomic ions quiz.
Which elements are liquid at room temperature?
Only two elements are liquid at room temperature, 25 °C (298 K): mercury and bromine. Mercury melts at -39 °C and bromine at -7 °C. Press Room temperature on the slider and the two liquid tiles, mercury and bromine, wobble.
A few metals come close. Cesium melts at 28 °C and gallium at 30 °C, below body temperature of 37 °C, so gallium melts in your hand. Francium probably melts near room temperature too, but no visible sample has ever existed to test it. This is why "mercury is the only liquid metal" is one of the myths about elements.
Eleven elements are gases at room temperature: hydrogen, nitrogen, oxygen, fluorine, chlorine and the noble gases from helium to radon. At 0 K helium is the only element that stays liquid.
How to read an element tile
Each tile shows four things. The small number at the top is the atomic number, the number of protons. The large letters are the chemical symbol, and the name sits below it. The last line is the value for the current Colour by mode. In Element type mode it is the atomic mass, in atomic mass units (u).
A mass in square brackets, such as [294] for oganesson, means the element has no stable isotopes; the number is the mass number of its longest-lived isotope. A small icon marks the state, and "?" means the state is predicted or unknown.
Open iron to read a full card. Iron is element 26, with electrons per shell of 2, 8, 14, 2 and 2 valence electrons. Its atomic mass, 55.845 u, is also its molar mass: 55.845 g of iron is one mole. The molar mass calculator adds these masses up for any formula.
Printable periodic tables
To print the periodic table, pick a Colour by mode and press Print. The page prints in landscape with the legend and the colours you chose. One page gives you an element-type table, an electronegativity chart or a melting point chart, depending on the mode. The printout includes the page address, so students can find the interactive version.
For classroom practice, the periodic table word search has a printable puzzle and answer key. The science printables page collects our other free charts and worksheets.
Frequently asked questions
How many elements are on the periodic table?
The periodic table has 118 elements, from hydrogen (number 1) to oganesson (number 118). IUPAC has confirmed all of them. Elements up to uranium (number 92) occur in nature, although technetium and promethium exist there only in tiny traces. Heavier elements are made in nuclear reactors and particle accelerators, some only a few atoms at a time.
Who created the periodic table?
Dmitri Mendeleev, a Russian chemist, published the first widely used periodic table in 1869. He ordered the elements by atomic weight, grouped those with similar properties and left gaps for elements not yet found. Gallium (1875), scandium (1879) and germanium (1886) later filled three of those gaps with properties close to his predictions.
What is the newest element?
The newest elements are nihonium (113), moscovium (115), tennessine (117) and oganesson (118). IUPAC confirmed their discovery in December 2015 and approved their names in November 2016. Oganesson has the highest atomic number of any known element. Only a handful of its atoms have ever been made, and each lasted less than a millisecond.
Why are there two rows at the bottom of the periodic table?
The two rows at the bottom are the lanthanides (57 to 71) and the actinides (89 to 103), which make up the f block. They belong in periods 6 and 7, but placing them in line would make the table 32 columns wide. Moving them below keeps it readable. The 57-71 and 89-103 tiles mark where they fit.
Which element is the most electronegative?
Fluorine is the most electronegative element, at 3.98 on the Pauling scale. It is a small atom one electron short of a full outer shell, so its nucleus pulls hard on shared electrons. Oxygen is second at 3.44. Francium is the lowest at 0.7. Pick Pull on electrons in Colour by to see the whole trend.
Which element has the highest melting point?
Tungsten has the highest melting point of any element that melts at normal pressure: 3695 K, or 3422 °C. That is why it was used for light bulb filaments. Rhenium is second at 3459 K. Carbon survives even hotter, but at normal air pressure it turns straight from a solid into a gas instead of melting.
How do I find the number of valence electrons?
For main-group elements, use the group number. Group 1 elements have 1 valence electron and group 2 elements have 2. In groups 13 to 18, subtract 10 from the group number, so chlorine in group 17 has 7. Helium is the exception, with 2. Tap any tile and its card lists the valence electrons.
Will more elements be discovered?
Probably. Laboratories in Japan, Russia and the United States are trying to make elements 119 and 120 by firing beams of lighter atoms at heavy targets. No element beyond 118 has been confirmed. Any new element would start period 8, and its atoms would likely last only a fraction of a second.
Credits and sources
- Element data: PubChem Periodic Table; IUPAC CIAAW standard atomic weights; NIST Atomic Spectra Database; IAEA Nuclear Data Section LiveChart; Royal Society of Chemistry periodic table; Wikipedia: Helium; Wikipedia: Carbon; Wikipedia: Arsenic; Wikipedia: Francium; Wikipedia: Astatine; Wikipedia: Aluminium; Wikipedia: Calcium.
- The table, atom models and colour scales are by 33Science, licensed CC BY 4.0. Credit 33Science and link to this page.