Random Chemical Element Generator
Pick a random chemical element from all 118 — or just one category of the periodic table.
There are 118 confirmed chemical elements, from hydrogen at number 1 to oganesson at 118, and this generator picks one of them at random. Press the button and you get a card with the element’s symbol in large type, its name, atomic number, standard atomic mass and category — alkali metal, noble gas, lanthanide and so on. Leave the category set to All and the draw covers the whole table; narrow it and the draw covers only that family, which is handy for quizzes, flashcards and revision games where “give me a halogen” is the actual question.
Pick a category if you want one, or leave it on All — then draw an element. Every element in the set has exactly the same chance.
After numbers instead? The Random Number Generator draws from any range. After words? Try the Random Word Generator, or drill times tables on the Multiplication Table page.
Quick answers
How does a random chemical element generator pick?
It holds all 118 elements in one list — or only the elements of the category you chose — and picks a position in that list with crypto.getRandomValues and rejection sampling, so every element in the set is equally likely.
Uniform means exactly that: in the All setting, each of the 118 elements has a 1 in 118 chance on every draw, regardless of how common or rare the element is in nature. Narrowing the category shrinks the list first — halogens draw from six elements, transition metals from 38 — and the pick is then uniform within that smaller list.
Why are some atomic masses in brackets, like (98) or (294)?
A bracketed mass means the element has no stable isotope and therefore no standard atomic weight. The number in brackets is the mass number of a selected long-lived isotope — (98) for technetium, (294) for oganesson — following the CIAAW convention.
A standard atomic weight is an average over the isotopes found in nature, weighted by how much of each turns up. Synthetic and highly radioactive elements have no natural mix to average, so any single figure would mislead. The bracket flags that honestly: this is one isotope’s mass number, not a measured average for the element as a whole.
What do the element categories mean?
The ten categories group elements by shared behaviour and position on the table: alkali and alkaline earth metals, transition and post-transition metals, metalloids, nonmetals, halogens, noble gases, lanthanides and actinides.
The groupings are practical shorthand. Halogens are eager reactants that form salts with metals; noble gases barely react with anything; lanthanides and actinides are the two pulled-out rows at the bottom of the table, mostly metals with similar, fiddly chemistry. Category boundaries involve some judgement for a handful of elements — this page uses the common textbook assignments throughout, and each element appears in exactly one category.
How to use
- Leave the category on All for a draw from all 118 elements, or choose one category — halogens, noble gases, lanthanides and so on — to narrow the draw.
- Press Pick an element. The card shows the symbol in large type, plus the name, atomic number, standard atomic mass and category.
- Press the button again for a fresh, independent draw — past picks do not change the odds of the next one.
- Use the reference table below the tool to see how many elements each category holds before you narrow a draw.
About this tool
The draw is uniform. Every element in the chosen set is held in one list, and the tool picks a position in that list using the browser’s cryptographic random source, with rejection sampling so no element gains an edge from rounding. That sounds like a detail, but it is the difference between a fair pick and a quietly rigged one: carbon and uranium are picked exactly as often as each other here, even though one is rather easier to find in the wild. Elements are weighted by nothing — not abundance, not usefulness, not how likely they are to come up in an exam.
The data is the standard table, stated plainly so you can check it. Atomic numbers run 1 to 118 with no gaps. Standard atomic weights are the conventional CIAAW/IUPAC values — hydrogen 1.008, iron 55.845, gold 196.97, uranium 238.03. Some masses appear in brackets, like (98) for technetium or (294) for oganesson: those elements have no stable isotope, so there is no standard weight to quote, and the bracketed number is the mass number of a chosen long-lived isotope instead. Each element sits in exactly one of ten categories, and the reference table below shows how the 118 divide among them — 38 transition metals at one end, six halogens at the other.
Everything happens in your browser. Nothing you draw is uploaded, sent anywhere or saved, and there is no history to clear. If random picks are your thing generally, the Random Number Generator linked below covers numbers; if you are in a language mood instead, the Random Word Generator there does the same trick with words.
The 118 elements by category
| Category | Elements |
|---|---|
| Alkali metal | 6 |
| Alkaline earth metal | 6 |
| Transition metal | 38 |
| Post-transition metal | 12 |
| Metalloid | 6 |
| Nonmetal | 7 |
| Halogen | 6 |
| Noble gas | 7 |
| Lanthanide | 15 |
| Actinide | 15 |
| All elements | 118 |
Frequently asked questions
How many elements are there?
118 confirmed elements, numbered 1 (hydrogen) to 118 (oganesson) with no gaps. The last four to be named — nihonium, moscovium, tennessine and oganesson — completed the seventh row of the table in 2016. Elements beyond 118 have been attempted but none is confirmed, so none appears here.
Are all elements equally likely to be picked?
Yes, within the set you choose. The pick uses crypto.getRandomValues with rejection sampling over the element list, so in the All setting every element has a 1 in 118 chance on each draw. Abundance in nature plays no part — hydrogen, which makes up most of the ordinary matter in the universe, is picked no more often than oganesson, of which only a handful of atoms have ever existed.
Where do the atomic masses come from?
They are the standard atomic weights published by CIAAW, part of IUPAC, checked November 2026. A few weights are conventional values for elements whose isotopic mix varies between sources — boron at 10.81, for instance. Bracketed figures such as (98) are not weights at all; see the note above the tool.
Why is hydrogen listed as a nonmetal when it sits above the alkali metals?
Position alone would put hydrogen with the alkali metals, but its behaviour is nothing like theirs — it is a gas that forms covalent bonds and can even gain an electron like a halogen. Most modern tables class it as a nonmetal, and this page follows that convention. It is a good reminder that categories describe behaviour, not just grid position.
Can I use this for a quiz or flashcards?
That is one of its best uses. Narrow the category, pick an element, and have players name the symbol, the atomic number or the category before revealing the card — or run it in reverse and quiz from the card itself. Because every draw is independent and uniform, no element is quietly favoured across a long quiz.
Is anything stored or sent anywhere?
No. The element list and the draw both live in your browser tab. Nothing is uploaded, logged or saved, and closing the tab clears the last pick.
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