Interactive Periodic Table
Explore all 118 chemical elements in the standard 18-group layout. Colour the table by category, state, block or electronegativity, filter and search, and click any element to see its atomic mass, electron configuration, melting and boiling points, density and discovery year.
Click a legend chip to filter, then click any element for its details.
Swipe the table sideways to see all 18 groups, or switch to List view.
Select an element
Click or tap any element in the table or list to see its properties.
How to use the Interactive Periodic Table
- Find an element: hover over the table, or type a name, symbol or atomic number in the search box and press Find.
- Pick a colour scheme: colour the elements by category, state, block or electronegativity.
- Filter: click one or more legend chips to highlight only those elements. Clear filters resets the view.
- Open the details: click any element to see its mass, electron configuration, electronegativity, melting and boiling points, density and discovery year.
- On a phone, swipe the table sideways or switch to List view and tap a column heading to sort.
Element categories on the periodic table
The colours in Category mode follow the most common classification used in school and university textbooks. Each group of elements shares typical physical and chemical properties.
| Category | Where it sits | Typical properties | Examples |
|---|---|---|---|
| Alkali metals | Group 1 (except H) | Soft, very reactive, one outer electron, form +1 ions, react with water | Li, Na, K |
| Alkaline earth metals | Group 2 | Reactive metals with two outer electrons, form +2 ions | Mg, Ca, Ba |
| Transition metals | Groups 3–12 | Hard, high melting points, coloured compounds, several oxidation states | Fe, Cu, Au |
| Post-transition metals | p-block metals | Softer metals with lower melting points | Al, Sn, Pb |
| Metalloids | Staircase between metals and nonmetals | Mixed properties, often semiconductors | B, Si, Ge, As |
| Reactive nonmetals | Upper right plus hydrogen | Poor conductors, form covalent bonds and negative ions | H, C, N, O |
| Halogens | Group 17 | Very reactive, seven outer electrons, form −1 ions and salts | F, Cl, Br, I |
| Noble gases | Group 18 | Full outer shell, colourless and mostly unreactive gases | He, Ne, Ar |
| Lanthanides | Period 6 f-block (57–71) | Similar silvery metals, used in magnets and phosphors | Nd, Eu, Gd |
| Actinides | Period 7 f-block (89–103) | All radioactive. Th and U occur in nature | Th, U, Pu |
How to read electron configurations
An electron configuration lists the subshells an atom's electrons occupy. Superscripts give the number of electrons in each subshell. To keep it short, the inner shells are written as the previous noble gas in square brackets. Iron (26 electrons) is [Ar] 3d6 4s2, which means the 18 electrons of argon plus six 3d electrons and two 4s electrons.
Subshells usually fill in the Aufbau (Madelung) order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p. A few elements break this pattern because a half-filled or completely filled d subshell is more stable:
| Element | Expected by Aufbau | Actual ground state |
|---|---|---|
| Chromium (24) | [Ar] 3d4 4s2 | [Ar] 3d5 4s1 |
| Copper (29) | [Ar] 3d9 4s2 | [Ar] 3d10 4s1 |
| Molybdenum (42) | [Kr] 4d4 5s2 | [Kr] 4d5 5s1 |
| Palladium (46) | [Kr] 4d8 5s2 | [Kr] 4d10 |
| Silver (47) | [Kr] 4d9 5s2 | [Kr] 4d10 5s1 |
| Gold (79) | [Xe] 4f14 5d9 6s2 | [Xe] 4f14 5d10 6s1 |
Configurations for elements beyond about fermium have not been measured and are theoretical predictions.
Periodic trends at a glance
- Atomic radius gets smaller from left to right across a period, because more protons pull the electrons closer. It grows down a group as new shells are added.
- Electronegativity rises from left to right and falls down a group. Fluorine (3.98) is the most electronegative element, so the top right of the table looks warmest in Electronegativity mode.
- Ionisation energy follows the same pattern as electronegativity. Noble gases are hardest to ionise and alkali metals are the easiest.
- Metallic character increases down a group and towards the left, which is why the metalloids form a diagonal staircase from boron to tellurium.
Values in this table are standard reference figures. Melting and boiling points are at 1 atm. Densities are near room temperature for solids and liquids, and at 0 °C and 1 atm for gases (in g/L). Values marked ≈ are estimates or predictions for elements that are scarce or very short-lived.
Frequently asked questions
How many elements are on the periodic table?
There are 118 confirmed elements, from hydrogen (atomic number 1) to oganesson (118). Elements 1 to 94 occur naturally on Earth, while the rest have only been made in laboratories or reactors.
How is the periodic table arranged?
Elements are ordered by atomic number, the number of protons in the nucleus. Rows are called periods and match the outermost electron shell, and the 18 columns are groups whose members share similar outer electron arrangements and chemical behaviour.
Why are the lanthanides and actinides shown below the table?
They fill the f subshell and would make the table 32 columns wide. Placing them in two separate rows keeps the table readable, and the gaps marked 57–71 and 89–103 show where they belong in periods 6 and 7.
What is electronegativity?
Electronegativity measures how strongly an atom attracts the electrons in a chemical bond. On the Pauling scale fluorine is highest at 3.98 and caesium among the lowest at 0.79. Noble gases such as helium and neon have no Pauling value because they rarely form bonds.
What do the s, p, d and f blocks mean?
The block tells you which type of subshell receives the last electron. Groups 1–2 and helium are the s-block, groups 13–18 the p-block, groups 3–12 the d-block, and the lanthanides and actinides the f-block.
Why do some atomic masses appear in square brackets?
Elements with no stable isotopes, such as technetium [98] or plutonium [244], have no standard atomic weight. The number in brackets is the mass number of their longest-lived isotope.
Which elements are liquid at room temperature?
Only bromine and mercury are liquid at 20 °C. Gallium (29.8 °C) and caesium (28.5 °C) melt just above room temperature, and gallium will melt in your hand.