Elemental

RNZ

To celebrate 150 years of the periodic table, get to know the back story of every element with our intrepid scientific hosts.

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98 episodes
Updated Dec 22, 2019

Episodes98

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Jun 20, 2019 · 12 min
Indium - Queen of the touchscreen
Indium is a very soft metal, and as indium-tin-oxide it is an indispensable part of the swipeability of touchscreens, says Allan Blackman from AUT in ep 38 of Elemental. If you use any kind of touch screen, whether smart phone or tablet, you have the element indium to thank. ITO is indium oxide with a tiny amount of added tin. ITO conducts electricity, thanks to the tin, and it is transparent to visible light. These two features make it the perfect addition to the toughened glass screen of capacitive touch screens. When you press your finger against the touch screen, an invisible grid of indium tin oxide senses the electrical disruption and this indicates where on the screen you have touched. It also enables you to swipe and pinch. ITO won't be so useful in future, as it doesn't work with flexible touch screens. Indium is also used in solar cells, says Professor Allan Blackman from AUT. Go to this episode on rnz.co.nz for more details
Jun 16, 2019 · 11 min
Hydrogen - 'number 1 in the Universe'
Hydrogen is the first element on the periodic table. It is the oldest, lightest and most abundant element in the universe, but on earth it is usually found in compounds such as water, says AUT's Allan Blackman, in ep 37 of Elemental. Hydrogen is the first element on the periodic table. It is the oldest, lightest and most abundant element in the universe, but on earth it is usually found in compounds such as water. Go to this episode on rnz.co.nz for more details
Jun 12, 2019 · 7 min
Holmium - obscure, but an important surgical laser
Holmium has interesting magnetic properties and is an important part of precise surgical lasers known as the 'Swiss Army knife' of lasers, according to Prof Allan Backman from AUT, in ep 36 of Elemental. The obscure element holmium is a lanthanoid with interesting magnetic properties. Named after the city of Stockholm (from Holmia, the Latin name for Stockholm) holmium finds use as a MRI magnet and in Ho:YAG lasers, which are homium-doped yttrium aluminium garnet lasers. These precise surgical lasers have been described as the Swiss Army knife of lasers, says Professor Allan Blackman from AUT. Go to this episode on rnz.co.nz for more details
Jun 9, 2019 · 13 min
Helium - rare on earth but universally abundant
Helium is the second most abundant element in the universe and possibly the most unreactive element on the periodic table, says Prof Allan Blackman from AUT, in ep 35 of Elemental. Did you know that helium is so light, that all the gas from your helium balloons escapes gravity and ends up in space? This is partly why it is rare on earth, but common in space, where it makes up 23 percent of the mass of observed matter in the universe. And while a helium-infused squeaky voice can be the life and soul of the party, in most other respects it is an unremarkable element. Odour? None. Colour? None. Taste? None. Toxic? No. Helium is possibly the most unreactive element on the periodic table - it doesn't even react with fluorine, the highly reactive Teflon element, says our resident expert Professor Allan Blackman from AUT. Go to this episode on rnz.co.nz for more details
Jun 6, 2019 · 6 min
Hafnium - helped land the first astronauts on the moon
Hafnium is named after Copenhagen and as it has a very high melting point it was used in the thruster nozzles of the Apollo Lunar modules, according to Elemental's Allan Blackman from AUT. Hafnium is named for Hafnia, the Latin name of Copenhagen. Ceramics that contain the transition metal hafnium (atomic number 72, symbol Hf) are among the highest melting substances known. The metal itself melts at 2230 degrees celsius, while hafnium carbide melts at 3200 degrees celsius. This makes it useful in plasma torches used to cut steel. Professor Allan Blackman from AUT says that a niobium-hafnium-titanium alloy also has a high melting point, which is why it was used in the thruster nozzles of the Apollo Lunar Modules. Go to this episode on rnz.co.nz for more details
Jun 2, 2019 · 14 min
Gold - a most desirable noble metal
Gold is highly valued for its colour as well as for being malleable and ductile, and as a noble metal it is unreactive and doesn't rust, says Allan Blackman from AUT in ep 33 of Elemental. The name gold comes from the Anglo Saxon word gold, but its chemical symbol Au comes from the Latin word aurum, meaning 'glow of sunrise.' Gold is the most malleable and ductile metal which is why it is beloved of jewellers. Its high value is a function of both its beauty and rarity. It is very unreactive, and so chemically aloof that it bonds with only one element - tellurium. The term 'acid test' is the use of nitric acid to determine whether a metallic object is gold - gold won't dissolve, but other metals such as silver will. Nanogold will turn fibres like wool a lustrous purple colour, says Professor Allan Blackman from AUT. Go to this episode on rnz.co.nz for more details
May 30, 2019 · 7 min
Germanium - important in the first transistors
Germanium is a metalloid that was a key element in early transistors and is now used in optical fibres and infrared night vision scopes, says Allan Blackman from AUT in ep 32 of Elemental. Germanium is a metalloid that was a key element in early transistors. The inventor of the first germanium-based transistors won a Nobel Prize. It is now used in optical fibres and infrared night vision scopes. Germanium (a metalloid with the atomic number 32) is named after Germany and was one of the elements whose existence on the periodic table was predicted by Dmitri Mendeleev. As a semiconductor it has an initial low conductivity, which can be boosted by increasing the temperature or 'doping' it with other elements. Professor Allan Blackman from AUT says that GeH4 is known as 'germane'. Go to this episode on rnz.co.nz for more details
May 28, 2019 · 7 min
Gallium - mysterious case of the disappearing spoon
Gallium is the second element named after France, is a key element in mobile phones & Blu-ray players & melts at body temperature, says Prof Allan Blackman in ep 31 of Elemental. Gallium is the second element on the periodic table named after France. It is a key element in mobile phones & Blu-ray players. It looks like silver but melts at body temperature, a feature that fun-loving chemists used to exploit to play pranks on people, says Prof Allan Blackman from AUT. They would craft a spoon from gallium, which would dissolve when the unsuspecting user went to stir the sugar in their cup of tea. Go to this episode on rnz.co.nz for more details
May 26, 2019 · 8 min
Gadolinium - plays a key role in MRI scans
Gadolinium has interesting magnetic properties and is used as a contrast agent in MRI scans, according to AUT's Prof Allan Blackman in ep 30 of Elemental. Gadolinium is named after the Finnish chemist Johannes Gadolin, who unfortunately didn't live to see the honour. Gadolinium (atomic number 64, symbol Gd) is a lanthanoid and as is the case with that group of elements, it was difficult to isolate. It has interesting magnetic properties and is used as a contrast agent in MRI scans, according to AUT's Prof Allan Blackman. Go to this episode on rnz.co.nz for more details
May 23, 2019 · 7 min
Francium - final naturally-occurring element to be discovered
Francium was the last naturally-occurring element to be discovered and has never been seen, says Prof Allan Blackman from AUT in ep 29 Elemental. Francium was the last naturally-occurring element to be discovered. It was found by French chemist Marguerite Perey in 1939, from an isotope of radioactive actinium. Marguerite had previously worked as a lab assistant with Marie Curie and became the first woman to be admitted to the French Academy of Sciences in 1962. Francium and actinium share the title of 'rarest naturally occurring element.' Francium has never been seen, so there are many basic things about it that we don't understand. Not surprisingly, says Professor Allan Blackman from AUT, it has no practical uses. Go to this episode on rnz.co.nz for more details
May 19, 2019 · 10 min
Fluorine - the non-stick element
Fluorine is a highly toxic green gas that is the main ingredient in non-stick teflon coatings. In ep 28 of Elemental, Prof Allan Blackman from AUT, says that fluorine has very different properties from fluoride. Fluorine has many nasty traits - it is a deadly poisonous gas that is so reactive that it will burn flesh. On the other hand, fluorine (Fl, atomic number 9) is a vital trace element in the human body and a key ingredient in many pharmaceuticals. It is commonly found in kitchens, in non-stick Teflon coatings. Curiously, Teflon was discovered accidentally. Fluorine is one of the chemicals in 1080, or sodium fluoroacetate, which is a naturally occurring compound that has become a key pest control tool in New Zealand, used to kill rats and stoats on conservation land. Professor Allan Blackman from AUT is at pains to point out that fluorine is not the same as fluoride. Fluorine is an element while fluoride, used in civic water supplies and toothpaste to help prevent dental cavities, is an ion with very different properties. Go to this episode on rnz.co.nz for more details
May 16, 2019 · 6 min
Europium - putting the security in the Euro
Europium is named after Europe and is responsible for a forgery-busting aspect of the Euro banknote, reports Prof Allan Blackman in ep 27 of Elemental. Europium is a truly European element. Not only is it named after the continent of Europe, but it is used a security feature for Euro banknotes. The Europium-containing ink is photoluminescent, and glows red under ultraviolet light, making it easy to spot forgeries printed with the wrong ink. Europium is rare on earth but rather more common on the moon, lending support to the idea that the moon and earth have different ancestries. Like all lanthanoid elements, europium has a torturous discovery story. It has a few niche uses including in now-obsolete cathode ray tubes TVs, energy-saving fluorescent lamps and light emitting diodes (LEDs). Professor Allan Blackman from AUT's favourite use of europium is as a growth-promoting film on glasshouses. Go to this episode on rnz.co.nz for more details
May 12, 2019 · 8 min
Erbium - through rose-tinted glasses
Erbium is named after a chemically famous Swedish village, and adds a rose-tinted glow to the periodic table, in ep 26 of Elemental with Allan Blackman from AUT. The chemical element erbium is one of eight lanthanoid elements discovered in a single mine in the small Swedish village of Ytterby. Four of those elements took their name from various combinations of letters of the name Ytterby: erbium, ytterbium, yttrium and terbium. It is used in welder's glasses to absorb the intense infrared light given off during welding, and erbium oxide provides the colour pink in coloured glass and spectacles. Erbium is important in optical fibres, acting to amplify light as it passes along the cable. Professor Allan Blackman from AUT says erbium is also used in lasers for skin resurfacing. Go to this episode on rnz.co.nz for more details
May 9, 2019 · 8 min
Dysprosium - hard to get
Dysprosium earned its name by being very hard to separate from other elements and has become very important in electric car motors. Join Allan Blackman from AUT in ep 25 of Elemental. Dysprosium gets its name from the Greek element dysprositos, meaning 'hard to get'. This is because like most lanthanoids, or rare earth elements, it is found in a mineral deposit tightly bound to various other lanthanoids. Dysprosium (chemical symbol Dy and atomic number 66) is very reactive, and as a pure metal it reacts with both air and water. It only has a few commercial uses, the main one being as a magnet in the drive motor of electric cars. The problem, as Professor Allan Blackman from AUT, explains is that there is not enough dysprosium to service the rapidly growing electric car market. Go to this episode on rnz.co.nz for more details
May 7, 2019 · 15 min
Curium & meitnerium - in honour of two pioneering women
There are only two chemical elements on the periodic table named after women: curium, in honour of Marie & Pierre Curie, & meitnerium after Lise Meitner. Allan Blackman from AUT introduces the women and their elements in ep 24 of Elemental. Marie Curie and Lise Meitner were pioneering women chemists, and the only two women to have chemical elements named in their honour. Curium, named after Marie Curie and her husband Pierre, is element number 96, which sits between americium and berkelium at the bottom of the periodic table. It is a radioactive, synthetic element that was discovered in 1944. It is responsible for much of the radiation of spent nuclear fuel. Marie Curie is the only person to have received two science Nobel Prizes: the Chemistry Nobel in 1903 which she shared with Pierre, and the Physics Nobel in 1911. Marie Curie's lab notebooks are still too radioactive to study without wearing protective clothing. Lise Meitner was born to Jewish parents in Vienna in 1878, and moved to Berlin to work in 1912. She was forced to flee from Nazi Germany to Sweden in 1938. Although Lise was nominated for a Nobel Prize 48 times she never won one. The synthetic element meitnerium is atomic number 109 and symbol Mt. It was discovered in 1982 but not named until 1997. Its German discoverers named it to "render justice to a victim of German racism and to credit in fairness a scientific life and work." Allan Blackman from AUT introduces the women & their elements. Go to this episode on rnz.co.nz for more details
May 5, 2019 · 12 min
Copper - essential, in moderation
Copper is a soft metal that is an essential element for enzymes and life, gives octopuses their blue blood and was often used to make coins. Allan Blackman from AUT has the lowdown on copper in ep 23 of Elemental. The metal copper is an important constituent of the human body - in the right amount. It's involved in enzymes, cellular respiration, and the synthesis of hormones and melanin, but too much or too little is bad for us. Copper is also why octopuses have blue blood. It can be found in nature as the pure metal (no refining needed) and the name copper originally meant 'metal from Cyprus.' Its chemical symbol is Cu and its atomic number is 29. On its own it is too soft to be very useful, but combined with either tin or zinc it creates the useful alloys bronze and brass, respectively. It has traditionally been used as a coinage metal. It is an excellent conductor, which is why it was used in copper phone lines and power lines. Go to this episode on rnz.co.nz for more details
May 2, 2019 · 9 min
Cobalt - goblin of the periodic table
Famous as the colour of blue glass and important in red blood cells, cobalt can form a permanent magnet and is vital for livestock. Allan Blackman from AUT talks about his favourite element in ep 22 of Elemental. The element cobalt's name comes from the German word kobold, meaning goblin or evil spirit. It was named by miners in 16th century Saxony who thought they had found deposits of silver but had actually found cobalt arsenide. Cobalt (symbol Co and atomic number 27) is a transition metal. It is ferromagnetic, which means it can form a permanent magnet. Cobalt is responsible for the cobalt blue paint pigment and Bristol blue glass. It is an essential trace element in animals as it part of vitamin B12. Foer a while it was added to beer to help it maintain a frothy head, but when coupled with poor diet and lots of alcohol it led to heart problems known as 'cobalt-beer cardiomyopathy.' Professor Allan Blackman from AUT says cobalt is his favourite chemical element as he studied it for his PhD. Go to this episode on rnz.co.nz for more details
Apr 28, 2019 · 7 min
Chromium - colourful and shiny
Chromium is a transition metal that gives colour to precious jewels, the shine to your car fender and your kitchen bench, but can also be a killer. All this and more in ep 21 of Elemental with Allan Blackman from AUT. Chromium, the element, gives us colour and shine - and helped Julia Roberts win an Oscar in 2000 for the movie Erin Brockovich. Chromium is the red in rubies, the green in emeralds and the pink in sapphires. It is the shine on your car fender and your stainless steel kitchen bench. Chromium III is widely used to tan leather*, while chromium XI (hexavalent chromium) has been used in textile dying and corrosion resistant coatings, and is very carcinogenic. The story of chromium the transition metal (Cr, number 24) with Professor Allan Blackman from AUT. *CLARIFICATON: Chromium XI is not used in leather tanning."Basic Chromium (III) Sulphate has been used for many decades to tan over 90 percent of the world's leather. It reacts with collagen covalently via the carboxyl groups associated with glutamic and aspartic acids to give a hydrothermally stable substrate, or leather." Information courtesy of the New Zealand Leather & Shoe Research Association Go to this episode on rnz.co.nz for more details
Apr 25, 2019 · 12 min
Chlorine - good for health, bad for health
Chlorine is the culprit in the 'case of the exploding trousers'. It is also well-known as a disinfectant and chloride ions are essential for life, but as DDT & CFCs, chlorine is bad news. Allan Blackman from AUT gives us the lowdown in ep 20 of Elemental. There was a spate of exploding trousers in New Zealand in the 1930s. The culprit turned out to be chlorine, in the form of sodium chlorate, used by farmers to kill ragwort. The element chlorine, it turns out, can be very, very good - and very, very bad - for your health. On the plus side it's vital for life. It is also an excellent disinfectant - the familiar chlorine smell of swimming pools, for example, and the widespread chlorination of drinking water. On the dark side, however, chlorine was used as the first chemical weapon. It is a key ingredient in CFCs (responsible for the depletion of the zone hole) and DDT (a damaging insecticide which caused problems for species such as birds of prey). Professor Allan Blackman from AUT introduces us to chlorine - chemical symbol Cl and atomic number 17. During the early 1930s New Zealand farmers were encouraged to use the highly inflammable chemical sodium chlorate as a weedicide against ragwort A report on the case of Richard Buckley's exploding trousers won an Ig Nobel prize in 2005. These are awarded for science that "first makes you laugh, then makes you think," and "cannot and should not be reproduced." New Zealander James Watson was awarded the Agricultural History Award for describing the health hazards of sodium chlorate, in a paper titled The Significance of Mr. Richard Buckley's Exploding Trousers: Reflections on an Aspect of Technological Change in New Zealand Dairy Farming between the World Wars. Go to this episode on rnz.co.nz for more details
Apr 21, 2019 · 10 min
Cerium - combustible and confusing
Cerium is the most abundant rare-earth element and pops up in self-cleaning ovens, cigarette lighter flints and spectacle glass. Find out more with Allan Blackman from AUT in ep 19 of Elemental. Cerium is one of the lanthanoids, also known as rare-earth elements. They are a series of chemical elements that sit on a separate line at the bottom of the periodic table. Cerium is the most abundant of the rare-earth elements and it pops up in spectacle glass and as a UV filter in window glass. It is also how self-cleaning ovens clean, and how cigarette lighter flints spark. All this and more as we explore cerium with Professor Allan Blackman from AUT. Go to this episode on rnz.co.nz for more details