By Ron B. Davis Jr., Georgetown University
Beryllium was first discovered in emeralds, the mineral beryl with about 2% chromium added to make it green. With an atomic number of 4, beryllium is the fourth smallest element in the table. Yet its natural occurrence in our universe and solar system is surprisingly small compared to the other elements in rows two and three of the periodic table.
Why Is Beryllium Scarce?
For starters, unlike hydrogen, helium, and lithium, beryllium just missed out on being produced during the early stages of the big bang. It was just a little too large to form under those conditions.
Next, we need to consider nuclear binding energy. Although a single stable isotope of beryllium (beryllium-9) does exist and it does have an even number of protons, its nuclear binding energy per nucleon is actually less than the lighter, doubly magic helium-4 nucleus. So there is no energetic benefit to the production of beryllium in stars unless that beryllium then goes on to fuse into another, larger, but even more stable nucleus.
This means that the beryllium that does form in stars, even stars as small as our sun, quickly goes on to become an even heavier element with more stable nucleus like carbon, oxygen or even iron. Here, beryllium serves more as an intermediate in stellar nucleosynthesis than a product, constantly being created, but also constantly being consumed.
Most beryllium in the universe is thought to have formed as larger atoms are broken down in collisions with cosmic rays in deep space—not the most efficient production mechanism. All of this adds up to make beryllium strikingly rare for such a small element. Still, what beryllium we have on Earth tends to accumulate as an oxide in certain minerals in the crust where we can get to it.
This article comes directly from content in the video series Understanding the Periodic Table. Watch it now, on Wondrium.
Was It Always Called Beryllium?
Tasting your work in the lab is a huge no-no today, but 200 years ago, it was all part of the job for chemists. French chemists originally noted that compounds of this element tended to have a sweet taste, and proposed name glucinium or glycinium (after the sugar glucose) and the elemental symbol ‘Gl’.
But other known elements also produced sweet-tasting compounds, so this name met a lot of resistance. By the time elemental beryllium metal was isolated in 1828 by Friederich Woehler and Antoine Bussy, most countries replaced the name glucinium with beryllium and the abbreviation ‘Gl’ with ‘Be’.
It’s probably a good thing that beryllium’s name changed, because we now know that ingesting too much beryllium is anything but a ‘sweet’ experience. That’s because even in small quantities, it can actually cause significant health problems.
No Care for Evolution
Evolution seems to have found no meaningful use for this element. Why might that be, while magnesium and calcium just below it are absolutely essential to human health? The likely answer to this is that beryllium being higher on the table has a greater electronegativity and higher ionization energies than magnesium and calcium. In some ways, this makes beryllium more akin to aluminum in what is sometimes called a ‘diagonal relationship’. If we collapse the s- and p-blocks, we can see this relationship better.
Aluminum, like beryllium, has little or no known biological importance in humans. Both of these elements in nature form strong oxide bonds that are more covalent in character than the other s-block metals we have explored. So the minerals containing these elements do not dissolve nearly as well in water. This causes their concentrations in ocean water to be orders of magnitude less than those of magnesium and calcium.
All this leads to bioavailable beryllium being very rare in our environment, perhaps that’s also why we never developed a way of efficiently eliminating beryllium from our bodies once it does get inside. What this means is that any small amount of beryllium that gets into our bloodstream can stay there for a very long time.
This exacerbates one of the health risks posed by beryllium exposure. Inhalation or ingestion of significant amounts of this element can cause a medical condition referred to as berylliosis. This is where the body stages an overactive immune response to beryllium that can cause medical complications lasting years, or even decades, as the immune system needlessly attacks trace beryllium that the body simply can’t get rid of.
Uses of Beryllium
Yet, in spite of the dangers of inhalation or ingestion of beryllium, it is extracted to the tune of well over 200 metric tons per year worldwide for use in making durable, light-weight metallic substances.
Beryllium and its alloys can be used to produce fuselage parts for aircraft, as well as electronics parts that might appear in computers, televisions and mobile devices that exploit the best properties of this element, and make the risk of working with it worthwhile.
Common Questions about Beryllium
One reason is that hydrogen, helium, and lithium were all produced in the early stages of the big bang, while beryllium was not formed because it is too large to be formed under such conditions. Due to the nuclear binding energy of beryllium-9 per nucleon, beryllium production in stars would also have no energetic benefit.
About two centuries ago, French chemists noticed a sweet taste in beryllium’s compound. Therefore, they proposed the name glucinium after the sugar glucose and the symbol ‘Gl‘. But since other known elements also produced sweet-taste compounds, the name met with much resistance, which eventually led to a change.
This is apparently due to the fact that beryllium is higher in the periodic table and has a higher electronegativity and ionization energy than magnesium and calcium. Accordingly, minerals containing this element hardly dissolve in water, so bioavailable beryllium is rarely found.