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Every element beyond uranium on the periodic table — 26 of the 118 — was made by people before it was found in any quantity in nature, if at all. The heaviest were created one atom at a time, in experiments that ran for months and produced atoms that survived for less than a second. Here’s how it’s done.
The basic idea: add protons
An element is defined by its number of protons. To make a new element, you have to get more protons into a nucleus. There are two main routes.
Route 1: neutron capture (up to fermium)
Bombard a heavy nucleus with neutrons. It absorbs one, becomes unstable, and a neutron inside it turns into a proton by beta decay — so the atomic number goes up by one. Repeat, and you climb the table step by step.
This is how neptunium and plutonium were first made (1940) from uranium, and how nuclear reactors make plutonium today. Einsteinium and fermium were discovered in 1952 in the debris of a hydrogen bomb test, where an enormous burst of neutrons pushed uranium up many steps at once.
But the method stops at fermium (100). The next isotopes decay by spontaneous fission too quickly to capture another neutron.
Route 2: fusion in a particle accelerator (element 101 onward)
For everything heavier, scientists smash two nuclei together hard enough to fuse. The atomic numbers add up:
- Oganesson (118): calcium (20) + californium (98)
- Tennessine (117): calcium (20) + berkelium (97)
- Nihonium (113): zinc (30) + bismuth (83)
A beam of the lighter nucleus is accelerated to around a tenth of the speed of light and fired at a thin target of the heavier one.
Why it’s so hard
The nuclei repel. Both are positively charged, so they have to be driven together with a lot of energy. But too much energy and the newly fused nucleus is so “hot” that it immediately flies apart.
Fusion is incredibly rare. Most collisions just scatter. For the heaviest elements, a beam running continuously for weeks — firing trillions of nuclei per second — might produce a single atom. The team that discovered nihonium ran their experiment for about nine years and recorded three atoms.
Targets are scarce. Heavy targets like berkelium-249 and californium-249 can only be made in a couple of high-flux reactors in the world, a few milligrams at a time, and some decay within months.
Products are short-lived. Superheavy atoms typically survive from milliseconds to seconds before decaying.
Two kinds of fusion
- “Cold” fusion (not the discredited energy claim) uses lead or bismuth targets with medium-weight beams like zinc. The compound nucleus has less excess energy. German and Japanese labs used it for elements 107–113.
- “Hot” fusion uses actinide targets with calcium-48 beams. Calcium-48 is unusually neutron-rich, which helps make heavier, slightly more stable isotopes. The Dubna lab in Russia used it for elements 114–118.
How do you detect one atom?
The new atom recoils out of the target and is separated from the far more numerous beam particles by magnetic and electric fields. It’s then implanted into a silicon detector. There, it decays — usually by emitting a series of alpha particles — each with a characteristic energy, time and position.
Scientists follow this decay chain until it reaches isotopes that are already known. If an atom’s chain lines up with known “daughter” nuclei, that fixes its atomic number and mass number. It’s a bit like identifying someone from their family tree.
How a discovery is confirmed
A joint working group of IUPAC and IUPAP reviews the evidence. They want:
- reproducible results, ideally confirmed by an independent laboratory;
- a convincing link to known nuclei;
- careful analysis of background events.
Only then do they assign credit and invite the discoverers to propose a name. See how elements get their names and the newest elements.
What’s next
Elements 119 and 120 are the current targets. They’d need beams heavier than calcium-48 — titanium-50, vanadium-51 or chromium-54 — because suitable targets beyond californium can’t be made in the necessary amounts. Estimates suggest production rates of perhaps one atom per several months of beam time. Several labs are trying, and finding either would open an eighth row of the periodic table.
Physicists also hope to approach the predicted island of stability, where some superheavy nuclei might live much longer than their neighbours.
Quick answers
What was the first artificially made element? Technetium (43), in 1937, from molybdenum bombarded with deuterons.
Why can’t we make large amounts of superheavy elements? They’re produced a few atoms at a time and decay within seconds.
Could new elements be useful? Probably not directly — they don’t last long enough. But they test our understanding of nuclear physics and of how relativity affects chemistry.
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