Lesser-Known Elements Trivia Quiz

Answer: Gadolinium

Gadolinium (Gd) was named after the mineral gadolinite (which was named after the Finnish chemist Johan Gadolin), and discovered by the Swiss chemist Jean Charles de Marignac in 1880. Its atomic number is 64. Gadolinium is found in other minerals as well, such as monazite, bastnäsite and cerite; in fact, it was via cerite that de Marignac was able to discover gadolinium oxide, as it contained more traces of the metal than gadolinite. It can mainly be found in China, India, Sri Lanka, Brazil and Australia, and is used in nuclear medicine and imaging as a magnetic contrast agent and in neutron radiography. Gadolinium compounds can also be used to make green phosphors, luminescent materials used in colour TV tubes, and tiny amounts of gadolinium can make more common metals such as iron more resistant to oxidation.

A rare-earth metal is a type of metal that is found in small traces in minerals, but because these traces are impure, huge amounts of ore are needed to obtain quantities of these metals with usable purity levels. The lanthanides are the elements numbered 57-71: lanthanum, lutetium and all those in between. Of note, yttrium and scandium are classified as rare earths, but NOT lanthanides.

Answer: Livermorium

Livermorium (Lv) is one of the newest elements in this quiz, and the only one that wasn't mentioned in Tom Lehrer's 'The Elements' as it was discovered in 2000, long after the song came out. It is a synthetic (artificial) element, number 116 in the Periodic Table, and is very radioactive; because it decays so quickly, and is very expensive to produce, little is known about its properties. The search for the 116th element began in 1977 at the Lawrence Livermore National Laboratory, when calcium-48 and curium-248 isotopes were used to obtain a reaction. However, it was not until 2000 that livermorium was finally synthesised in Dubna in Russia.

Chalcogens are the group of elements known as the 'oxygen family', and can be found in Group 16 of the Periodic Table; other known chalcogens include oxygen (although some scientists do not consider it to be part of the group as it behaves very differently to the others), tellurium, selenium, polonium and sulphur. Oxygen, tellurium, selenium and sulphur are all primordial elements, i.e. they have existed on Earth from the dawn of time. They all have six valence electrons (electrons in the outer shell of an atom that can help form chemical bonds, as long as the outer shell is open).

Answer: Hafnium

Hafnium (Hf) is named for Hafnia, the Latin name for Copenhagen, and its atomic number is 72. Dimitri Mendeleev had predicted its existence as a heavier analogue of titanium and zirconium back in 1869, and it was found by Dutch physicist Dirk Coster and Hungarian chemist Georg von Hevesy in Norwegian zirconium ores in 1923. It is mainly used to make control rods for nuclear reactors, which are used to control the fission rate of nuclear fuel; because it is difficult to obtain, it is also expensive; its price rocketed after the Fukushima Nuclear Disaster in 2011, following a drop in the demand for hafnium-free zirconium. It is also used in plasma cutting because it can shed electrons into the air, and in microprocessors.

The transition metals are in Groups 3-12 (although some argue that the Group 12 elements don't count) of the Periodic Table, and have good electrical conductivity in common. They have valence electrons in two shells, and form colourful compounds. Some of the more well-known ones are zinc, copper and nickel.

Answer: Rubidium

Rubidium (Rb) is the 37th element of the Periodic Table and is a soft, whitish-grey metal that is denser than water, unlike its predecessors lithium, sodium and potassium. German chemists Robert Bunsen (as in the burner) and Gustav Kirchhoff discovered rubidium in 1861 using flame spectroscopy and gave it its name because it emitted red light. Rubidium salts can be used in fireworks to give them a purple colour; it is also used in atomic clocks and imaging technology, such as positron emission tomography (PET) scans.

The soft, highly reactive, alkali metals are on the far left of the Periodic Table, and you may remember them from high school chemistry class as those metals (sodium and potassium, usually) that fizzed when your teacher dropped them into water. For safety reasons, rubidium, francium and caesium are not used in these demonstrations, although we did see a video that showed what happened when caesium was dropped into water. It blew the container to bits!

Answer: Astatine

Astatine (At) has an atomic number of 85 and is notable for being one of the rarest, if not the rarest, elements that occurs in nature, mainly as the decay product of other elements. Astatine-211 is undergoing research as a potential radiopharmaceutical for cancer treatment, but its scarcity and short half-life makes it tricky to work with; the scientist Patricia Wallace Durbin described it as 'miserable to make and hell to work with'. Several chemists attempted to discover the 85th element as predicted by Mendeleev, but it was not until 1940 that a group of American scientists synthesised it in California. It is so radioactive that it effectively vaporises itself.

The halogens are in the 17th column of the Periodic Table and also include fluorine, chlorine, bromine, iodine and the relatively recent tennessine. They get their name from their ability to form salts when combined with metals. The exact nature of astatine is uncertain as it displays some metallic behaviour and is thought to be similar to silver, but has not been officially confirmed as a metal.

Answer: Samarium

Samarium (Sm) is not named after the Biblical land of Samaria, but after samarskite, a Russian mineral named after the Russian mining engineer Vassili Samarsky-Bykhovets; it is therefore the first element to be named after a person. It is element number 62 in the Periodic Table, and the French chemist Paul-Émile Lecoq de Boisbaudran is credited with its discovery in 1879. It is found in the same minerals as gadolinium (gadolinite, cerite, bastnäsite etc.) and has a similar density and hardness to the more commonly known zinc.

Samarium is used in powerful permanent magnets, in combination with cobalt; rare-earth magnets are considered to be the strongest type of magnet in terms of magnetic fields, though they are also brittle and need coating. Samarium-cobalt magnets are also highly resistant to demagnetisation. Samarium was also used in early lasers, and is used as a catalyst to make plastics decompose.

Answer: Thorium

Thorium (Th), the 90th element in the Periodic Table, was discovered by Morten Thrane Esmark, a Norwegian mineralogist, and named by the Swedish chemist Jöns Jacob Berzelius, who is also credited with discovering selenium and cerium. Esmark discovered a rare black mineral on the Norwegian island of Lovoya and his father sent it to Berzelius, who named the mineral thorite and isolated a new element from it, which he called 'thorium' after Thor, the Norse god of thunder. Fittingly, it is very electropositive. Thorium was initially used to make gas mantles and crucibles, amongst other things, but usage of thorium as an element was phased out due to its radioactivity, and it is mainly used today in the form of thorium dioxide. The uses of thorium dioxide include nuclear fuel in pellet form, a stabiliser in tungsten electrodes, and glass manufacturing.

The actinides, or actinoids, are the elements between actinium and lawrencium, numbered from 89 to 103. With the exception of lawrencium, they are located in the f-block of the Periodic Table. They are similar to lanthanides, highly dense and have a silvery colour.

Answer: Antimony

Antimony (Sb) was originally known as 'stibium', and is the 51st element of the Periodic Table. The origins of its name are unknown; 'against aloneness' and 'monk killer' have been suggested, although the latter is unlikely as, while antimony is poisonous, it has lower toxicity than arsenic. It has been used for centuries, initially in cosmetics such as kohl, and may date as far back as Ancient Egypt in 3100 BC; Pliny the Elder also mentioned it in his writings. Predominantly found in China, it is primarily obtained by roasting the mineral stibnite. Today, it is used in flame-retardant compounds, bullets, paint and lead-acid batteries, in combination with lead. Fans of the fantasy webcomic 'Gunnerkrigg Court' may recall that 'Antimony' is the full name of the heroine Annie Carver.

The pnictogens are the elements in the 15th column of the Periodic Table, and are also known as the nitrogen family. As well as nitrogen, the group also contains arsenic, bismuth, phosphorus and moscovium. Their stability makes them good compound formers. Arsenic is also notorious for its poisonous nature, while phosphorus is used in chemical weapons.

Answer: Strontium

Strontium (Sr) has an atomic number of 38 and is named after Strontian, a village in Scotland near the place where it was discovered by the Northern Irish chemist Adair Crawford and Scottish chemist William Cruickshank in 1790. Humphry Davy later used electrolysis to isolate strontium from its mineral of strontianite. In the 19th century, strontium salts were used in what was known as the Strontian Process to separate sugar from molasses; strontium was also initially used to make cathode ray tubes for televisions, though this has decreased over time as cathode ray tubes have been phased out. Today, strontium salts are used to give fireworks a deep red colour. While naturally-occurring strontium isn't dangerous in itself, strontium-90, a synthetic isotope, is extremely dangerous and carcinogenic, and is a product of nuclear fallout. Edward Teller even proposed it as a potential weapon for contaminating the German food supply during the Second World War.

The alkaline earth metals are a group of shiny, reasonably reactive metals found in Group 2 of the Periodic Table. As well as strontium, the group also includes barium, radium, calcium, beryllium and magnesium. Most of them occur in nature, though radium is a byproduct of the decay of uranium and thorium.

Answer: Hassium

Hassium (Hs) is the 108th element of the Periodic Table and was discovered in 1984; because of its high atomic number, it is known as a 'superheavy' element, a collective name for the elements that come after lawrencium (the final actinide and element number 103).

It is considered to be a heavier version of osmium. It was named after the German state of Hesse, where it was discovered at the GSI Helmholtz Centre for Heavy Ion Research in 1984 by a group of German scientists led by Peter Armbruster. Hassium, like astatine, decays very quickly, making its properties hard to research.

It has only been produced in small quantities in laboratories.