All 118 Elements

Every element that has been confirmed to exist has a page here — all 118, from hydrogen to oganesson, with no gaps and no stub entries waiting to be filled in later.

What is on an element page

Each page opens with a data card, ordered the way a question usually arrives. The standard atomic weight comes first. Then the address — group, period, block — and the electron arrangement, in noble-gas shorthand and again as the occupancy of each shell. Then the physical facts: how dense it is, what phase it is in at 20 °C, and the two temperatures at which it changes phase. Then the chemical disposition: electronegativity, the energy needed to take the first electron off it, and the oxidation states it is usually found in. The year it was identified closes the card. Below that sits the full isotope table from the NIST/CIAAW compilation: every isotope with a published relative atomic mass, and its natural abundance where it has one.

Beside that runs a hazard block drawn from a fixed eleven-item vocabulary — reactive with water, pyrophoric, flammable, oxidising, corrosive, irritant, acutely toxic, accumulating in the body, carcinogenic, asphyxiant, radioactive — with each term defined in the same words wherever it appears. Those are statements about what a substance is. Nothing on this site describes how to handle, prepare or work with anything.

The rest of the page is written: what the element actually is, how it was found, where it turns up, and what makes it different from the ones next to it in the table.

Three ways to find one

The periodic table on the home page is the fastest route if you know roughly where an element sits. Every tile is a link, and the fill colour tells you its family before you click.

The lists below are the alternative, and on a phone they are usually the better one. The first groups all 118 by family, in the order the colour key uses; the second is a plain A-to-Z. Both carry the symbol, the name and the atomic weight, so a quick lookup often does not need a click at all.

If you want a whole family rather than one element — every halogen, every lanthanide, everything in period 3 — the family and period hubs collect them with the trends across the set laid out together.

About the numbers

The full account of where each figure came from, and the date it was captured, lives on the sourcing page. Before you open any single element, three awkward facts run through the whole set, and each page they touch shows the awkwardness rather than tidying it away:

• Fourteen carry an interval instead of a single atomic weight — a published range, because the isotope mix genuinely differs between one natural source and another. Argon and lead were the two most recent to move, in 2017 and 2020.
• Thirty-seven have no stable isotope, and thirty-four of those give up on an average entirely: the figure in the weight slot is a mass number in brackets, belonging to whichever isotope survives longest.
• The ten heaviest — 109 through 118 — have no experimentally characterised chemistry. They are coloured as unknown here rather than being given the family colour their position predicts, because a colour is a claim and that claim has not been tested.

How the 118 break down

Thirty-four of them are transition metals, which is the largest family by a wide margin and the reason the middle of the table is so wide. The lanthanides and actinides account for fifteen each. At the other end, there are only six alkali metals, six alkaline earth metals and six noble gases — three of the most chemically distinct families in the table are also three of the smallest.

Twelve elements are reactive nonmetals, and between them they make up almost everything living things are built from. Seven are metalloids, sitting on the staircase between metal and nonmetal and behaving like whichever one the situation calls for. Seven more are post-transition metals, the soft, low-melting ones like tin and lead.

Two are liquid at 20 °C — mercury and bromine — and eleven are gases, or twelve if you count oganesson, whose gaseous state is a prediction nobody has been able to test on the handful of atoms ever made. Everything else is a solid, including several that no one has ever seen in a quantity large enough to look at.