Random Element Generator

What the random element generator does

You need an element. Maybe you are building a quiz and you do not want to keep picking the same twelve you happen to like. Maybe you are revising and you are tired of starting at hydrogen every single time. Maybe you just want to name a server after something.

This hands you one of the 118 chemical elements, or a hundred of them if you want to read down a list until one stops you.

What follows is the more interesting part. Why the number is 118 and not something else, why the last two rows of the table read like a map instead of chemistry, and why pulling elements out of order is a better way to learn them than going in order.

How to use it

1. Choose how many you want. Anywhere from 1 to 100. For revision, three or four at a time works better than thirty.
2. Press Generate. A fresh set every time.
3. Narrow it down with the boxes underneath if you want elements starting with a certain letter or carrying a certain sound.
4. Press Copy to take the whole set with you.

Why the list stops at 118

Every list on this website is a selection. Somebody sat down, decided what deserved to be there, and left the rest out.

This one is not. There are 118 elements and all 118 are here. Hydrogen at one end, oganesson at the other, nothing skipped.

So the question is not what got left out. The question is why the number is 118 at all.

And here is the thing that catches people. 118 is not a fact about the universe. It is a fact about us. It counts the elements somebody has managed to find or build, and then persuade a committee about. The number sat at 92 for a long time. It reached 109 in the mid nineties. That is why you will still find element generators today telling you, quite confidently, that there are 109 elements in the periodic table. They were right once. They just stopped looking.

In November 2016 IUPAC signed off on the names for 113, 115, 117 and 118, and the table got the edge it has today.

That edge will move again.

The seam running through the table

Cut the 118 somewhere other than the end and it gets better.

The first 94, hydrogen through plutonium, all turn up naturally on Earth. Not all of them usefully. Six of those 94 exist in amounts so small that calling them natural is close to a technicality. Technetium, promethium, astatine, francium, neptunium and plutonium show up as stray atoms in uranium ore and almost nowhere else.

Technetium is the good story there. It sat as a hole in the table for decades because nobody could find any. Eventually people stopped digging and made it instead, in 1937, which made technetium the first element humans manufactured rather than found. It was named for the Greek word for artificial. Somebody had a sense of humour.

Everything from 95 upward exists only because a person built it. And once you know that, look at what those ones are called:

• Americium
• Berkelium
• Californium
• Dubnium
• Darmstadtium
• Livermorium
• Moscovium
• Nihonium
• Tennessine

America. Berkeley. California. Dubna. Darmstadt. Livermore. Moscow. Japan. Tennessee.

That is not chemistry. That is a map of where the particle accelerators were, and who was paying for them. The right hand edge of the periodic table is Cold War physics funding written down in a form your chemistry teacher makes you memorise.

So the table has a seam in it, right after plutonium. Everything to the left of it was here before us. Everything to the right is our handwriting.

Taking the last element apart

Pull oganesson out of the list and look at what you are actually holding.

To make it, a team at Dubna fired calcium ions at a californium target for 1,080 hours. That is 45 days of continuous bombardment, roughly sixteen billion billion calcium ions into a target the size of a coin.

They got three atoms.

Each one lasted about seven ten thousandths of a second before it fell apart. Fewer than six atoms of oganesson have ever existed, as far as anyone knows, and every one of them is long gone.

It is named for Yuri Oganessian, who led the work and who was alive when they named it. He still is. That makes oganesson one of only two elements ever named after a living person. The other is seaborgium.

Now think about the poster on a classroom wall. Oganesson gets a box exactly the same size as oxygen. One of those two is roughly a third of the mass of the planet you are standing on. The other one has been seen three times, each time for less than a camera flash.

That is worth carrying around. The table looks like a filing cabinet, all the boxes the same, everything equally solid. It is not. It runs from the air in your lungs to a rumour that lasted less than a millisecond.

Starts with, contains, and ends with

The boxes do what they say, but each one is reading a different part of the entry, and that trips people up.

• Starts with reads the first letter of the element name. There is no element beginning with J, Q or W, so those three come back empty every time. Four letters return exactly one element each: K gives you krypton, U gives you uranium, V gives you vanadium, X gives you xenon. That is the whole list for those letters. Nothing is broken.
• Contains searches the name and the symbol in the brackets together, and it ignores capitals. This is the box worth playing with. Type ium and 78 of the 118 come back, which is two out of every three elements on the table. Type W and you get tungsten, even though tungsten does not start with a W, because its symbol does.
• Ends with is the one to skip on this page. Every entry here carries its symbol in brackets, so the last character of all 118 of them is a closing bracket. Type a letter and you get nothing back. This one is on us and it is on the list to fix.

While you are here, one piece of trivia that falls out of all this. J and Q do not just fail to start an element. Neither letter appears anywhere in any of the 118 names. Not once, in any position. Every other letter of the alphabet is in there somewhere.

You also do not need to press Generate after every change. Type in any of the boxes and the results redraw as you go.

How an element gets picked

Nothing clever is happening, and that is deliberate.

The elements come from a list our team researched and checked by hand against the set IUPAC recognises. When you press Generate, that list is narrowed to whatever matches the boxes you typed in, and elements are drawn at random from what is left. Inside a single batch you will never see the same element twice.

There is no weighting. Oxygen and oganesson have exactly the same chance, which is either a nice piece of democracy or a small crime against chemistry, depending on your mood.

All of it happens on your own device. Nothing you type is sent anywhere.

Why random beats reading down the table

Most people who land on a page like this are revising, so this part is for them.

In 2006 Roediger and Karpicke ran an experiment that should be better known than it is. Students studied a passage. One group then reread it. The other group tested themselves on it instead, with no feedback, no answers, just recall. Same material, same number of rounds.

Five minutes later, the rereaders did better.

A week later it had flipped completely, and the group that had tested themselves was ahead by a distance.

Here is the part that should bother you. Rereading made students more confident they would remember. It felt like learning. It just was not learning. The people who felt worst about their chances were the ones who actually knew the material seven days later.

Going down the periodic table in order, hydrogen, helium, lithium, is rereading. It feels productive. You are recognising, not recalling, and recognising is the easy one.

Pulling a random element and trying to say the symbol out loud before you look is testing. It feels worse. That is the point.

Order is also a crutch. Go H, He, Li every time and part of what you learn is the sequence itself, so the answer arrives because the last one did. Break the order and that scaffold is gone, and you find out fast which ones you actually know. For most people that turns out to be the first twenty, gold, and whatever was on the last exam.

Questions people ask

Does this include every element?

Yes. All 118 that IUPAC currently recognises, from hydrogen to oganesson, including the synthetic ones that only ever existed for a few milliseconds inside an accelerator. If you find a generator that says 109, it stopped updating around 1996.

Is it Aluminum or Aluminium?

Both, depending on where you are standing. Our list uses the American spellings, Aluminum and Cesium. IUPAC prefers Aluminium and Caesium, and most of the world outside the United States writes them that way. Sulfur is the one that went the other way, and the s spelling is now the standard everywhere. The Contains box will find any of them if you search a fragment like alumin.

Will the list ever be longer than 118?

Probably, and people are working on it right now. Element 119 does not exist yet. It has a placeholder name, ununennium, which is Latin for one one nine. It would open the eighth row of the table and be the first new element named since 2016.

A team at RIKEN outside Tokyo has been chasing it for years. Two of the chemists there, Hiromitsu Haba and Kouji Morimoto, visit their local shrine at the start of each year and drop exactly 119 yen into the collection box. For luck. These are people who run a particle accelerator for a living and they are still hedging with a shrine, which somehow makes me trust them more.

For scale, when RIKEN made nihonium it took something like four trillion collisions to produce three atoms. 119 is harder than that. Russia, the United States, China and Germany are all going for 119 and 120 as well. So bookmark this page and it might be 119 long one day, which is a strange thing to be able to say about a list.

Can I use this to build a quiz for my class?

That is one of the reasons it is here. Pull twenty, ask for symbols, and you get a spread that does not quietly favour the elements you personally find interesting. Your own bias is the thing a random draw is actually protecting against.

Why did my search come back empty?

Nine times out of ten it is the Ends with box, which cannot work on this page because every entry finishes with a bracket. After that, check whether you asked for J, Q or W in Starts with. No element uses them.

References

1. Öhrström, L. and Reedijk, J. (2016). Names and symbols of the elements with atomic numbers 113, 115, 117 and 118 (IUPAC Recommendations 2016). Pure and Applied Chemistry, 88(12), 1225 to 1229. https://doi.org/10.1515/pac-2016-0501
2. Oganessian, Yu. Ts. et al. (2006). Synthesis of the isotopes of elements 118 and 116 in the 249Cf and 245Cm + 48Ca fusion reactions. Physical Review C, 74(4), 044602. https://doi.org/10.1103/PhysRevC.74.044602
3. Roediger, H. L. and Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249 to 255. https://doi.org/10.1111/j.1467-9280.2006.01693.x
4. Nelson, F. (2024). How Japan took the lead in the race to discover element 119. ACS Central Science, 10(9), 1669 to 1673. https://doi.org/10.1021/acscentsci.4c01266
5. IUPAC. Periodic Table of the Elements. https://iupac.org/what-we-do/periodic-table-of-elements/