Podcast: Play in new window | Download
This week, we try to interact with helium, even though it really doesn’t want to. Plus, we explore the occult side of chemistry, as described by the theosophists.
Featured above: The emission spectrum of helium, which Lockyer and Janssen discovered in 1868.
Apologies for the slightly tinny voice quality on this episode. I thought I could get away with an unshielded mic — I won’t be making that mistake again!
Peak Helium: In the intro, I alluded to some “recently discovered subterranean pockets” of helium. There’s one in particular, a reserve of natural gas that was discovered in Tanzania that contains incredible amounts of helium. The discovery of this pocket of gas was a very big deal — without it, there was enough helium to last a few decades, but not longer. Even better news: That reserve was recently found to be twice as large as originally thought.
The point however, still stands. Pretending that underground reserves of chemicals can last forever is a foolish position.
Theoretically Speaking: I didn’t get a chance to go deeper into the strange properties that researchers like to play around with, but that’s what show notes are for. When a special variety of helium is cooled down near absolute zero, it displays some truly strange behaviors — like climbing up the sides of its container, or falling straight through the bottom. This video is well worth your 90 seconds:
Why does the sun shine? That tiny amount of mass that’s converted to light and heat during a fusion reaction does so according to Einstein’s most famous equation,e=mc2. The amount of energy e, measured in joules, that can be liberated from a given amount of mass m, measured in kilograms, is equal to m multiplied by the speed of light c squared. c is provided as 299,792,458 meters per second.
Why does the sun really shine? All right, you got me.
A Noble Gas: Helium practically never combines with other elements. But impractically, helium can combine with sodium under 300 million atmospheres of pressure to form disodium helide.
Wheels Within Wheels: Neutrons are the final piece of the atomic puzzle… but we can go smaller. After all — what makes up protons and neutrons and electrons?
The Smallest Atom: In both hydrogen’s episode and this one, I’ve been careful to avoid calling either one the “smallest element,” even though it’s a pedantic hill to die on. Here’s why: Hydrogen is less massive than helium, but helium technically takes up less space. This is because the two electrons and two protons in helium experience greater attraction to one another than hydrogen’s one of each — so helium densely packs all its subatomic particles into a smaller radius.
I Can’t Believe They Screwed That Up: “Ozone” is not an atom, by the way, despite what’s written in Occult Chemistry. It’s a molecule made of three oxygen atoms bound together, or O3.
Caveat Emptor: I feel like it’s important to mention that the helium tanks a civilian can rent or purchase for private use typically have a significant amount of oxygen added to the tank, so that anyone who inhales a great deal — intentionally or otherwise — will not die. But as far as I can tell, the tanks that professional balloon-fillers have access to is the pure stuff.
Let It Go: There’s a lot more to learn about helium if you’re interested, and there’s at least one entire blog dedicated to this element alone. It’s a great resource, but maybe not the most unbiased source, since they’re also trying to sell tanks of helium to anyone who will have them. But if you’re just a casual reader, check out what happened at the first Macy’s Thanksgiving Day Parade, for instance!
As elements go, helium is kind of an all-star. It’s used in medicine, as an essential component of MRI machines; it’s important in the manufacture of silicon wafers for computers;1 arc welders use helium during construction of ships, cars, and buildings.2 It even exhibits some weird behaviors that are studied in cutting-edge physics. Not to mention, helium has probably been a part of most of the parties you’ve ever attended, inside those balloons.
There’s just one problem: Helium is so useful that we’re quickly burning through our limited supply. Some recently discovered subterranean pockets of helium ensure that the situation isn’t critical, but at the rate we currently use it, we have one or two centuries’ worth of helium left — and we didn’t even know it existed 150 years ago. 3
The good news is, we do know how to make more. The bad news is, the process can level an entire city.
You’re listening to the Episodic Table of Elements, and I’m T. R. Appleton. Each week, we’ll take a look at the fascinating stories behind one element on the Periodic Table.
Today, we’re taking a deep breath and looking at Element 2, Helium.
In the early 19th century, Joseph von Fraunhofer was the finest lenscrafter in the world. He was a true prodigy, displaying outstanding skill from a young age, despite never receiving much of an education. To assess his work, he’d focus a newly ground lens on a candle’s flame, and because his tools were so precise, he could see details that no one had before.
One of the things this let him discover was that when a chemical element is heated until it glows, it emits a unique pattern of light, acting like a fingerprint that precisely identifies the element.
The new tool that performed this task was called the spectroscope, and it was integral to the success of early chemistry. It allowed for accurate analysis of mineral samples taken from the earth, and it directly led to the discovery of caesium and rubidium in 1861.4 But a few years later, two great minds had the same idea: to turn the spectroscope toward the sky.
In 1868, Pierre Janssen and Norman Lockyer each independently analyzed the light of the sun by spectroscope, and discovered something strange: A series of Fraunhofer Lines, as the light patterns came to be called, that didn’t match any known chemical. (This was another case of Multiple Discovery, as discussed last episode.) Janssen noted this with curiosity, but Lockyer took the bold step of naming the new element. Since it was discovered in the sun, the element inherited its name from the Greek word for sun: Helios.5
Few elements on the periodic table are as aptly named as helium. Some amount of it was created during the Big Bang, along with all the hydrogen in the universe, and a small amount of lithium. But the sun makes its own fresh supply, right on site.
A star is born when a cloud of hydrogen gathers in space, the atoms attracted to each other by the force of their own gravity. Eventually, they pack together so tightly that strange things begin to happen.6 As the cloud increases in density, pressure and heat begin to rise. Hydrogen atoms start smashing together and glomming on to each other, a process called “fusion.” When four atoms of hydrogen slam together, they create a single atom of helium.7 8 The helium atom is slightly less massive than the four hydrogen atoms combined, because a tiny amount of that mass is converted to energy in the forms of light and heat. This is why the sun shines.
This fusion reaction is happening constantly in stars like the sun. With every second that passes, 700 million tons of hydrogen are burned into helium ashes.9 Amazingly, we’ve been able to replicate this process here on earth — but only by detonating hydrogen bombs. And when that happens, helium conservation is probably the last thing on anyone’s mind.
This transmutation within the sun can only go on as long as there’s a supply of hydrogen to convert into helium. In about 5 billion years, our sun will run out. But it won’t snuff out like a flame at that point — no, something much more interesting starts to happen then. When there’s no more hydrogen to burn, the sun will use its helium as fuel, smashing those atoms together into carbon and oxygen.10
Stars more massive than the sun will continue in this way, eventually creating elements as heavy as iron. The sun is too small for that to happen but something else very interesting will happen when it starts burning helium. It will become what’s known as a “red giant,” mostly because, well, it will become red and gigantic.
In fact, it will grow so large that the sun will completely engulf the orbits of Mercury, Venus, and eventually, Earth. But don’t worry — the oceans will boil away and Earth will be rendered uninhabitable a long time before that happens. 11
Let’s zoom in to see how helium is a little more complex than what we looked at last time.
You might remember that hydrogen is a pretty simple little atom. The simplest, in fact, with a single electron buzzing around a single proton. Helium, meanwhile, has two protons — because, remember, the number of protons defines the element. But a new kind of particle has joined the protons in our nucleus: The neutron.
While electrons carry a negative electrical charge, and protons have a positive one, neutrons — as the name suggests — are entirely neutral, with no electrical charge at all. This turns out to be pretty important: Without neutrons padding the space between positively-charged protons, they would repel each other and rip the atom apart. In the entire universe, nothing more complex than hydrogen would be able to form.12
While they don’t carry an electrical charge, neutrons are pretty massive, contributing about as much to an atom’s weight as a proton does. This is why helium has an atomic weight of approximately 4 — there are four particles in the nucleus — but an atomic number of 2 — only two of them are protons.13 Electrons, you might remember, are extremely small, and add almost nothing to an atom’s weight.
Neutrons are the final piece of the atomic puzzle. Every element we examine from here on out will consist of some number of protons, neutrons, and electrons — and that’s it.
Speaking of electrons, the two that helium possesses are what make it act so different from hydrogen.
Helium is the first of the noble gases, so called because they’re too prim and proper to be seen mingling with any of those other low-class elements. Seriously. Helium, neon, and the others in group 18 practically never combine with other atoms to form molecules.
Remember how hydrogen has one electron that creates a shell around its nucleus? It turns out that shell is only half-full. It can actually fit two electrons in that shell. And it really, really wants to find another electron to fill its shell.
This is why hydrogen is so reactive. It’s so desperate to fill its electron shell that, if you just add a little heat, two hydrogen atoms will make an arrangement with any nearby oxygen atom, and they lend each other some electrons. This provides a full electron shell for the two hydrogen atoms and one oxygen atom. Thus, H 2 O. 14
It sounds quite diplomatic, but from our perspective, that’s exactly the reaction that’s responsible for hydrogen’s explosive nature.
Helium, on the other hand, already has two electrons in its shell. It is quite satisfied and won’t be needing any electron handouts from other, more volatile atoms, thank you very much. It is a pure individualist, needing nothing from nobody.
With lithium, things get pretty exciting again — but we’ll save that for next episode.
Helium may be four times as massive as hydrogen, but it’s still the second-lightest element in the universe. Much like hydrogen, any amount that finds its way into the atmosphere will “slip the surly bonds of earth,”15 floating away into outer space.
This is why people were skeptical of Lockyer and Janssen’s discovery of helium within the sun: Without a sample on earth to test against, it was practically impossible to verify. Some scientists dismissed it as no discovery at all. But other people saw an opportunity to play the element game a little fast and loose.
In 1879, there was a solar eclipse, and some scientists turned their spectrometers toward the outer edges of the sun. They found new unidentified lines in the sun’s corona. Much like helium, this was presumed to be a new element, fittingly dubbed “coronium.”
But Annie Besant and Charles Leadbeater took things to the next level in 1908, when they published one of chemistry’s strangest books. It was called Occult Chemistry: Investigations by Clairvoyant Magnification into the Structure of the Atoms of the Periodic Table and Some Compounds.16
It was a landmark text of the theosophy movement, a mystical philosophy that took hold in the late 19th century. Its founders didn’t dispute contemporary findings of science, but rather, tried to incorporate that into their divine wisdom.17 Of course, this was alongside their beliefs in spiritualism, astral projection, and seances.
It’s important to note that this was an unprecedented time in history. For the average person, the line between the scientific and the spiritual certainly seemed to be blurring. Scientists were discovering a plethora of invisible forces that governed our lives — x-rays, radioactivity, and the atomic structure that underlies everything in our world. Why should those exist, but not telepathy, clairvoyance, and our immortal souls? In fact, what if these mysterious new forces somehow linked the world of the spiritual with the world of the physical?
From our current perspective, it’s easy to scoff at these beliefs. But this was one way people dealt with a confusing world that changed every day. It helped that the theosophists capably mimicked the style and tone of scientific papers, filling Occult Chemistry with diagrams, measurements, and jargon that sounded just as reputable as any legitimate science — until it went straight to wackyland at the drop of a hat.
For instance, at one point, the authors write,
…a chemical atom of ozone appears as an oblate spheroid, with the contained spiral much compressed and widened in the centre; the spiral consists of three snakes, one positive and two negative, formed in a single revolving body. On raising the chemical atom to the next plane, the snake divides into three, and being enclosed in its own egg.”
Without getting into the peculiarities there, these were some precise observations to declare. But this was a time before electron microscopes and particle accelerators. How did Besant and Leadbeater conduct these observations? They claimed that by using their third eye, they could directly observe the world at the atomic level.18
It was during one of these observations that the theosophists discovered a new element of their own. In Occult Chemistry, they described it like so:
Occultum was observed by us in 1895, and, finding that it was so light, and so simple in its composition, we thought that it might be helium … When, however, helium itself came under observation in 1907, it proved to be quite different from the object before observed, so we dubbed the unrecognised object Occultum, until orthodox science shall find it and label it in proper fashion.”
The two never actually intended to deceive. As one blogger wrote of the two, “Leadbeater and Besant are often called charlatans, but they were not. Their idiocy was sincere.”19
Obviously, “orthodox science” never did find evidence of occultum, and coronium wasn’t a new element, either. That turned out to just be what iron looks like at a few million degrees celsius.20 Neither was nebulium, or lucium, or dozens of other proposed elements that turned out to not actually exist.
But it’s worth acknowledging that the periodic table, concrete as it looks now, existed for a long time in a state of flux and chaos, and with that came all the mistakes, quick conclusions, and even opportunism that accompanies any burgeoning field of science. It’s half a miracle that we even know which elements exist with any certainty whatsoever.
And that’s a great thing, because if you’re going to collect something, it sure better exist.
Last time, we did a little kitchen chemistry to add hydrogen to our collection of chemical elements. Helium is much easier to collect: Just go to your local party supply store and ask for a balloon.
But you might worry that such a vendor may be disreputable: The party store only needs helium that’s good enough to keep a latex balloon afloat for less than a day. Who knows whether it’s quality helium, the kind that a discerning collector would want?
Luckily, those who trade in chemical elements — professionally I mean, I’m talking about chemists here — chemists have a system in place to grade the quality of their product. But it’s not as simple as saying, “This helium is 95% pure,” because we’re mostly dealing with much higher purities than that. Many industries need to know whether a sample is 99.997% pure or 99.999% pure. It’s very precise work that they’re doing!
Since repeating “nine” so many times would be confusing and unhelpful, pure elements are given grades like “4.5” or “5.0.” The number before the decimal point says how many nines are in the percentage-grade purity of the element, and the number after the decimal point represents the number after the last nine. So Grade 4.5 helium is 99.995% pure while Grade 5.0 helium has five nines, followed by a zero — or 99.999%.21
Grade 6 helium is as pure as it gets, and it’s used in the ultra-precise work of semiconductor manufacture and chemical research. And, I’m sorry to say, the lowest purity of helium is casually called “balloon grade,” since chemical applications don’t get much more frivolous than party decorations.
But unless you’re a true perfectionist, you don’t need to worry much about a contaminated supply. It’s actually considerably more difficult to provide low-grade helium than “Five Nines.”
The reason is because helium is most often compressed and stored in tanks, so it can be transported as efficiently as possible. When it’s compressed beyond a certain pressure, helium liquifies — and this liquid helium is, by nature, extremely pure. It would actually be more expensive for suppliers tointroduce impurities!22
So rest easy knowing that you can easily get a reasonably pure sample of helium for your collection. Just make sure to store it in something more leak-proof than a latex balloon.
Thanks for listening to the Episodic Table of Elements. Next time, we’ll investigate the highs and lows of lithium.
Music is by Kai Engel. To read show notes and the transcript for this episode, comment, and learn more, visit episodic table dot com slash helium.
This is T. R. Appleton, reminding you to find a way off-planet before we’re consumed by the flames of a dying sun.
- Time, There’s A Helium Shortage On — And It’s Affecting More Than Just Balloons. Tim Newcomb, August 21, 2012.
- The Fabricator, What’s Up With Helium For Welding Applications? Dan Davis, December 3, 2012.
- Wired, That Dire Helium Shortage? Vastly Inflated. Brendan Cole, June 29, 2016.
- Access Science, A Brief History Of Spectroscopy. Maurice M. Bursey, 2017.
- Periodic Tales: A Cultural History of the Elements from Arsenic to Zinc, Hugh Aldersey-Williams. pp. 191-192.
- Space.com, Main Sequence Stars: Definition & Life Cycle. Nola Taylor Redd, May 5, 2015.
- Berkeley Lab’s Smoot Group, Formation Of The High Mass Elements: What Happens Inside A Star?
- Quora, What Is The Process To Convert Hydrogen To Helium? Harry Chikoo, June 12, 2016.
- Stanford Solar Center, Is The Sun Shrinking? Amara Graps.
- Cornell University: Ask An Astronomer, What Happens To The Helium Formed In The Sun? David Bernat, February 10, 2016.
- Phys.Org, The Sun Won’t Die For 5 Billion Years, So Why Do Humans Only Have 1 Billion Years Left On Earth? Jillian Scudder, February 13, 2015.
- Nature, Possible Existence of a Neutron. James Chadwick, February 27. 1932.
- Commission on Isotopic Abundances and Atomic Weights, Helium.
- Khan Academy, Hydrogen Bonding In Water.
- I don’t want to be glib in cribbing Reagan’s remarks following the Challenger disaster, so let’s call it a reference to the original poem by David P. Brown.
- The book is available in its entirety at Project Gutenberg.
- Encyclopedia Britannica, Theosophy. John Gordon Melton, last updated February 25, 2015.
- Chemistry World, Clairvoyant Chemistry. Philip Ball, March 15, 2013.
- A Synthetic Environment, Adyarium and Occultum. June 26, 2007.
- Technology Through Time Issue #43: Coronium.
- The Zephyr Blog, Grades Of Helium: The Differences And Uses. Kathi Leiden, February 26, 2016.
- CryoGas International, Increased Availability Of Balloon Grade Helium: An Opportunity For Independent Distributors. Phil Kornbluth, February 2016. Originally from Kornbluth Helium Consulting, backed up on this site for archival purposes.
2 Replies to “2. Helium: Above All That”
Is helium an group 2 element? Eric Scerri discussed this placement in his book.