Einsteinium
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40 free Einsteinium trivia questions with answers — science & nature quiz, new questions added Oct 2026.
Einsteinium is one of the strangest entries on the periodic table. Nobody set out to make it: element 99 turned up by accident in the debris of the first hydrogen bomb test in 1952, and almost everything about it since has been a fun fact. This quiz covers the whole story: the explosion that created it and the people who sifted through what was left, the famous physicist it is named after, where it sits among the elements, and how tiny amounts are made today. You will also meet its odd habits, from the way it destroys its own samples to the unlikely places it has turned up. The questions start easy and get harder, so they suit curious beginners, chemistry students revising the elements and quiz fans hunting for facts worth repeating. Every answer comes with a short explanation.
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Q 01A speck of einsteinium flew aboard NASA's Surveyor 5 probe to help analyse the surface of which world?
The Moon
The Moon met einsteinium less than two years before Apollo 11 landed nearby. The heavy isotope calibrated Surveyor 5's soil analyser because its signal stood clear of the lighter elements being measured.
Q 02Why did the 1952 discovery of einsteinium in hydrogen bomb fallout go unannounced for about three years?
It was a military secret
It was a military secret: the United States kept the find quiet during the Cold War arms race and declassified it in 1955. By then the team had remade element 99 in the laboratory and published that work instead.
Q 03Einsteinium honours a physicist whose 1921 Nobel Prize rewarded which discovery, rather than relativity?
The photoelectric effect
The photoelectric effect won Albert Einstein the prize. He explained it in 1905, the same miracle year in which he published his special theory of relativity.
Q 04Einsteinium is too scarce and short-lived to sell, so what are today's tiny batches of element 99 made for?
Scientific research
Scientific research is the only customer: chemists study the metal or use it as a target for making heavier elements. Americium, four places lighter, is the one inside household smoke detectors.
Q 05Einsteinium-253 releases about 1,000 watts of heat per gram, making a pure sample do what in the dark?
Glow by itself
Einsteinium can glow by itself, lit by the energy of its own decay. The same radiation wrecks the metal's crystal structure, which makes its basic properties very hard to measure.
Q 06Albert Einstein, the namesake of einsteinium, was offered the presidency of which country in November 1952?
Israel
Israel offered Einstein its largely ceremonial presidency in the same month that a hydrogen bomb test created the element later named for him. He did not want the office.
Q 07Atoms of which heavy metal inside the first hydrogen bomb each captured 15 neutrons to become einsteinium?
Uranium
Uranium nuclei soaked up 15 neutrons apiece in the blast, then seven beta decays walked them up the periodic table to element 99. Capturing so many at once had been thought extremely rare.
Q 08Tons of which material from the blasted Pacific atoll were shipped to America to recover more einsteinium?
Coral
Coral from the atoll held far more of the new element than the first samples did. Even so, the team ended up with fewer than 200 atoms of it.
Q 09Roughly how much einsteinium do the world's few specialised nuclear reactors produce in a typical year?
About a milligram
About a milligram a year is the world's entire output, made by bombarding heavy elements with neutrons. Purifying it then cuts the usable amount roughly tenfold.
Q 10How did scientists first collect einsteinium from the mushroom cloud of the 1952 hydrogen bomb test?
Planes with filters
Planes with filters flew straight through the cloud, and the first atoms of element 99 turned up on those papers. The method had already caught a new form of plutonium in the debris.
Q 11Which symbol does einsteinium carry on the periodic table, after its discoverers first proposed plain E?
Es
Es became the official symbol after the chemistry body IUPAC dropped the single letter. The discoverers had proposed E when they named element 99 in 1955.
Q 12Like most of its neighbours on the periodic table, einsteinium is a soft metal of which colour?
Silvery
Silvery is the look of nearly every metal in this heavy corner of the periodic table. Einsteinium also melts at about 860 °C, low for its neighbourhood.
Q 13Which element, named after the Italian builder of the first nuclear reactor, was found alongside einsteinium?
Fermium
Fermium, element 100, turned up in the same bomb debris. It is the heaviest element that can be made by bombarding lighter ones with neutrons.
Q 21Which American scientist, co-discoverer of a record 12 elements, led the team that identified einsteinium?
Albert Ghiorso
Albert Ghiorso had a hand in finding every element from number 95 to number 106. He trained as an electrical engineer, not a chemist, and came to the work through building radiation detectors.
Q 22Which Tennessee laboratory's High Flux Isotope Reactor is one of the world's two main sources of einsteinium?
Oak Ridge
Oak Ridge irradiates tens of grams of curium at a time to end up with a mere speck of einsteinium. The only comparable reactor is at Dimitrovgrad in Russia.
Q 23Einsteinium probably formed two billion years ago in a natural nuclear reactor found in which African country?
Gabon
Q 14Which element, named after the father of the periodic table, was first made by bombarding einsteinium in 1955?
Mendelevium
Mendelevium, element 101, began as just 17 atoms knocked out of a target of about a billion einsteinium atoms. It was the first element ever made one atom at a time.
Q 15Which Pacific atoll, now home to a concrete dome of radioactive debris, saw the blast that made einsteinium?
Enewetak
Enewetak lost a whole island to the 1952 test, which left a seawater-filled crater more than a mile wide. The dome was built in the late 1970s.
Q 16Einsteinium belongs to which series of radioactive metals, printed in a row beneath the main periodic table?
Actinides
Actinides take their name from actinium, the first of the series, and every one of them is radioactive. Einsteinium behaves like the rest, usually giving up three electrons.
Q 17Which 1905 equation by the physicist honoured in einsteinium has been called the world's most famous?
E = mc²
E = mc² says a little mass holds enormous energy, which is what a hydrogen bomb releases. Einsteinium was born in the first such blast.
Q 18Einsteinium was announced in August 1955, a few months after what had happened to Albert Einstein?
He had died
He had died that April, aged 76, so he never saw his element made public. The discoverers had proposed the name while he was still alive.
Q 19In animal studies, einsteinium that reaches the bloodstream settles mostly in which part of the body?
The bones
The bones take up about 65 per cent of the einsteinium that reaches a rat's blood. Very little gets that far, though: rats absorb only about 0.01 per cent of what they swallow.
Q 20Einsteinium sits directly below which rare-earth metal on the periodic table, sharing much of its chemistry?
Holmium
Holmium and einsteinium have almost the same density, about 8.8 grams per cubic centimetre, even though an einsteinium atom is far heavier.
Gabon's Oklo ore deposit ran as a natural reactor about two billion years ago. Any einsteinium made there decayed away long before anyone could look for it.
Q 24A rival team at the Nobel Institute for Physics in which country raced einsteinium's American discoverers?
Sweden
Sweden's team made element 100 by firing oxygen at a heavy target and published in 1954. The Americans kept priority because their bomb-test results came first, so they chose the names.
Q 25At a 1955 atomic energy conference in which Swiss city was einsteinium first announced to the world?
Geneva
Geneva hosted the first international atomic conference that August, and one of the discoverers presented the new element there in person.
Q 26Ions of which element were fired at einsteinium in a failed 1985 attempt to create element 119?
Calcium
Calcium ions struck a target of einsteinium-254 in a particle accelerator, but not one atom of element 119 appeared. That form of einsteinium was picked because it is heavy and lasts for months, not days.
Q 27Einsteinium-253 decays into an element named after which university city, where einsteinium was identified?
Berkeley
Berkeley gave its name to berkelium, which einsteinium-253 turns into at a rate of about three per cent a day. That steady change contaminates every sample.
Q 28Einsteinium's namesake signed a 1939 letter warning which US president that Germany might build atomic bombs?
Roosevelt
Roosevelt responded by creating an advisory committee, the start of America's atomic bomb effort. Einstein later told a friend that signing the letter was the one great mistake of his life.
Q 29Which Hungarian-born physicist co-devised the hydrogen bomb design whose 1952 test created einsteinium?
Edward Teller
Edward Teller worked out the two-stage design with Stanisław Ulam in 1951. He became known as the father of the hydrogen bomb.
Q 30Which New Mexico laboratory both built the 1952 hydrogen bomb and helped identify einsteinium in its debris?
Los Alamos
Los Alamos shared the detective work with two other American laboratories. The bomb's design effort was codenamed Project PANDA, so the new element was jokingly nicknamed Pandemonium.