How to use
- Click any element in the table, or type a name, symbol or atomic number in the search box.
- Read the details panel at the top.
- Click a category below the table to highlight all elements of that type.
Options explained
- Atomic mass
- Standard atomic weight in unified atomic mass units (u); for unstable elements, the mass of the longest-lived isotope.
- Electron configuration
- Written with the preceding noble-gas core in brackets, for example [Ar]4s2 3d6 for iron.
- Electronegativity (Pauling)
- How strongly an atom attracts electrons in a bond; fluorine is highest at 3.98.
Element categories
Colours in the table follow PubChem’s classification of the 118 elements:
| Category | Count | Examples |
|---|---|---|
| Alkali metals | 6 | Li, Na, K, Rb, Cs, Fr |
| Alkaline earth metals | 6 | Be, Mg, Ca, Sr, Ba, Ra |
| Transition metals | 38 | Fe, Cu, Ag, Au, Zn, Hg |
| Post-transition metals | 11 | Al, Sn, Pb, Bi |
| Lanthanides | 15 | La, Ce, Nd, Eu |
| Actinides | 15 | Th, U, Pu |
| Metalloids | 7 | B, Si, Ge, As, Sb, Te, Po |
| Nonmetals | 7 | H, C, N, O, P, S, Se |
| Halogens | 6 | F, Cl, Br, I, At, Ts |
| Noble gases | 7 | He, Ne, Ar, Kr, Xe, Rn, Og |
At room temperature 11 elements are gases, only two are liquids — bromine and mercury — and the rest are solids, apart from nine short-lived superheavy elements whose state has never been measured.
Common elements at a glance
| Element | Atomic mass | Melting point | Density |
|---|---|---|---|
| Hydrogen (H) | 1.0080 | −259.34 °C | 0.00008988 g/cm³ |
| Nitrogen (N) | 14.007 | −210.00 °C | 0.0012506 g/cm³ |
| Oxygen (O) | 15.999 | −218.79 °C | 0.001429 g/cm³ |
| Sodium (Na) | 22.990 | 97.80 °C | 0.97 g/cm³ |
| Chlorine (Cl) | 35.45 | −101.50 °C | 0.003214 g/cm³ |
| Iron (Fe) | 55.84 | 1,537.85 °C | 7.874 g/cm³ |
| Copper (Cu) | 63.55 | 1,084.62 °C | 8.933 g/cm³ |
| Silver (Ag) | 107.868 | 961.78 °C | 10.501 g/cm³ |
| Gold (Au) | 196.97 | 1,064.18 °C | 19.282 g/cm³ |
| Mercury (Hg) | 200.59 | −38.83 °C | 13.5336 g/cm³ |
| Lead (Pb) | 207 | 327.46 °C | 11.342 g/cm³ |
Gas densities are at 0 °C and normal pressure, which is why they look so small next to the metals.
Frequently asked questions
Where do the numbers come from?
From PubChem, the US National Library of Medicine’s chemistry database (public domain). Melting and boiling points are shown in °C and kelvin.
Why are lanthanides and actinides shown below the table?
It is the usual layout that keeps the table 18 columns wide. They belong in periods 6 and 7 — the marked cells 57–71 and 89–103 show where.
Can I use it on a phone?
Yes. Swipe the table sideways to see all 18 columns, or use the search box to jump straight to an element.
Privacy
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