Sciency Words: Island of Stability

October 13, 2017

Today’s post is part of a special series here on Planet Pailly called Sciency Words. Each week, we take a closer look at an interesting science or science-related term to help us expand our scientific vocabularies together. Today’s term is:

ISLAND OF STABILITY

According to Star Trek: Voyager, in the 24th Century there will be 246 elements on the periodic table. In one episode, the Voyager crew discovers element 247, and to their astonishment that element is stable.

Here in the 21st Century, on modern day Earth, there are only 91 naturally occurring elements. Element 43, technetium, and everything above element 92, uranium, have to be produced artificially. And these artificial elements are all unstable. Some of them, especially the really, really high numbered ones, are so unstable that they’re effectively useless.

When an atomic nucleus gets too big, the so-called strong nuclear force is no longer strong enough to hold the whole thing together. You can also run into problems if you don’t have a comfortable balance of protons and neutrons. At that point, when atoms are too big or improperly balanced, they start shedding nuclear particles until they can stabilize themselves. This process is called radioactive decay.

If you want, you can draw a chart with the number of protons in an atom along one axis and the number of neutrons along the other. But charts are boring, so let’s draw a map instead.

Physicist Glenn Seaborg (for whom element 106, seaborgium, is named) was apparently a big fan of maps. I imagine he and J.R.R. Tolkein would have gotten along well. In the 1960’s, Seaborg started referring to groups of atomic isotopes by “geographical” names, and these names have stuck.

On the map above, the landmass stretching up from the bottom left corner represents all the stable and semi-stable isotopes. This “Peninsula of Stability” is surrounded by a “Sea of Instability.” But somewhere out in that sea, according to Seaborg and others, certain very large atoms might theoretically become stable. These atoms would have just the right balance of protons and neutrons to hold themselves together despite their extreme size. These “magically” stable isotopes are represented by the Island of Stability.

Physicists have been trying to find the Island of Stability for decades now, but it seems to be perpetually just over the horizon. It was once predicted that elements 110 and 114 might be stable. They’re not. I remember reading that element 118 might turn out to be stable. It didn’t. Now there’s a prediction about element 120. We’ll have to wait and see about that one.

Also there’s a possibility that we’ve been skirting along the island’s coast, so to speak. Maybe if we just add a few more neutrons to some of the unstable elements we’ve already found, they’ll stabilize. Maybe. More on that in next week’s Molecular Monday post.

Personally, I think Star Trek: Voyager was on to something. My prediction is that the Island of Stability will be found all the way out at element 247, and I recommend the IUPAC name it Janewayium.


Molecular Monday: Boron Isn’t Boring

October 2, 2017

Welcome back to another edition of Molecular Mondays, a special biweekly series here on Planet Pailly combining two of my least favorite things: chemistry and Mondays.

At some point long, long ago, I read a book about the periodic table of the elements. Chapter five was about boron, and what I remember learning was that boron is kind of useless. Certain boron-containing compounds are used in cleaning detergents, and while boron is not particularly toxic to humans, it’s deadly to insects, so it makes a good insecticide.

And that was basically it. Nothing more to know. Time to move on to chapter six: carbon.

So when the news came out that the Curiosity rover had detected boron on the surface of Mars, my initial reaction was “who cares?” But then I read more, and I soon realized that I’d been grossly under-informed about the fifth element from the periodic table.

First off, finding boron on Mars posed a real challenge. The Curiosity rover used an instrument called ChemCam, which basically zaps rock samples with a laser and performs a spectroscopic analysis on the resulting rock vapor.

According to this paper published in Geophysical Research Letters, scientists were looking for two spectral lines, both in the ultraviolet part of the spectrum, which are characteristic of boron: 249.75 nm and 249.84 nm. Annoyingly, iron also produces a spectral line at 249.96 nm, so ChemCam can only confirm boron’s presence in samples that have low iron content, which are hard to come by on Mars. Iron oxide is basically everywhere.

But despite this difficulty, boron was detected. Why should I or anyone else care? Because it was detected in veins of sedimentary rock, meaning that at some point long ago when Mars still had lakes and rivers and oceans of liquid water, boron must have been mixed into that water (likely in the form of borate, a compound of boron and oxygen).

Again, why should anyone care? Because some of the fragile molecules necessary for life decompose in open water, but borate can help stabilize those molecules, allowing them to combine to form RNA. Boron itself is not incorporated into our modern DNA, but its presence here on Earth may have helped life get started—and if boron was present on Mars, mixed into ancient Martian waters, it could have helped life get started there too.

Could have. We still don’t know for sure, but as I’ve hinted previously I am planning a little trip to Mars aboard my imaginary spaceship. Stay tuned. I’ll be sure to let you know if I find anything.


Molecular Monday: The Four Elements

September 18, 2017

For some reason, I’ve been thinking a lot lately about the original elements, the four elements Aristotle wrote about many millennia ago: fire, water, wind, and earth. Of course we no longer think of these as elements in the chemical sense. Instead we have the periodic table of elements, with well over a hundred elements identified so far.

But just for fun, I thought I’d try to find a way to connect the old Aristotelian elements to the first four modern chemical elements: hydrogen, helium, lithium, and beryllium. Here’s what I came up with:

  • Hydrogen: Let’s start by associating hydrogen with “water.” The word hydrogen actually means “water maker.” It got its name because in 1783, Antoine Lavoisier demonstrated that the oxidation of hydrogen gas produced water (this experiment also proved that water is not elemental).
  • Helium: Helium was first detected in the solar spectrum in 1868 and was thus named after the Greek word for “sun.” The Sun is pretty fiery, so my first instinct was to make helium represent “fire.” But I’m going to go with “air” instead, because of helium’s use in balloons and airships.
  • Lithium: As I’ve written about previously, lithium was first discovered using a method called a flame test. When a chemical substance is burned, the color of the flame can be used to determine the chemical’s identity. Lithium burns with a characteristic bright crimson flame. Therefore, I’m choosing to associate lithium with “fire.”
  • Beryllium: Beryllium was first identified in 1798 as a component of the mineral beryl, specifically a form of green beryl we all know as an emerald. So I think I can safely wrap this little game up by connecting beryllium with “earth.”

So how did I do? Do you agree with the connections I came up with? Are there other connections we could think up that might work better?

Okay, maybe this was more of an exercise in creativity than science. I’m okay with that. And besides, in the half-hour I spent researching for this post, I learned a few things about the first four elements of the periodic table that I didn’t know before. That’s always a plus.

Anyway, next time on Molecular Monday, we’ll be talking about boron. Now I wonder if I can find some way to associate boron with the girl from The Fifth Element.


Sciency Words: Spectroscopy

September 2, 2017

Welcome to a special Saturday edition of Sciency Words, because sometimes life gets in the way of regular blogging schedules. Each week (normally on Fridays) we take a closer look at some science or science-related term so we can all expand our scientific vocabularies together! Today’s term is:

SPECTROSCOPY

What color is it? It sounds almost like a childish question, but as we look out into space, trying to study the Sun and other stars and distant planets, we can learn a great deal just by figuring out what color things are.

The science of spectroscopy has a long history, beginning with Isaac Newton. In the late 1600’s, Newton demonstrated that pure white light can be split apart into a rainbow of color using a prism. Newton called this a spectrum, from the Latin verb specto, meaning “I observe” or “I see.” (According to my trusty Latin-English dictionary, the noun spectrum also meant “apparition” or “ghost.”)

Over the decades and centuries to come (click here for a detailed timeline), scientists used increasingly sophisticated combinations of lenses, mirrors, and prisms to study Newton’s spectrum in greater detail. They also experimented on a wide variety of light sources: sunlight, starlight, firelight, and even electrical sparks.

An especially noteworthy experiment in 1752 showed that burning a mixture of alcohol and sea salt produced an unusually bright yellow band in the middle of the spectrum (we now know this to be a emission line for sodium). And in 1802, another experiment on sunlight revealed multiple dark bands in the Sun’s spectrum (which we now know are absorption lines for hydrogen, helium, and other elements in the Sun’s photosphere and corona).

All the colors of the rainbow, except a few are missing. This is an absorption spectrum.

It wouldn’t be until the early 20th Century, with the development of quantum theory and, specifically, Niels Bohr’s model of the atom, that anyone could explain what caused all these spectral lines.

No rainbow, just a few specific colors. This is an emission spectrum.

In Bohr’s atom, the electrons orbiting an atomic nucleus can only occupy very specific energy levels. When electrons jump from one energy level to another (the true meaning of a quantum leap), they either emit or absorb very specific frequencies of light. The light frequencies are so specific that they act as a sort of atomic fingerprint.

And so today, as we look out into the universe, seeing the glow of stars and the absorption patterns of planetary atmospheres, it’s possible for us to identify the specific chemical elements we’re seeing, even across the vast distances of space, simply by asking what color is it?


Where Does Fat Go When You Exercise? (A Molecular Monday Post)

June 5, 2017

Exercise is good for you, I guess. It’s probably one of the better options for anyone who’s trying to lose weight. But when you exercise, where does the weight go, physically speaking?

The first time someone asked me this question, my best guess was that it had something to do with Einstein’s E = mc2 equation, the equation that allows matter to be converted into energy. But I knew that couldn’t be right. That’s more of a nuclear physics thing, and the human body is not a nuclear reactor.

The actual answer has to do with chemistry. Rather simple chemistry. This is a triglyceride molecule:

Okay, it is sort of a complicated-looking molecule. Don’t worry. Your body knows what to do with it, even if your brain doesn’t.

The important thing, in relation to today’s question, is that triglyceride is composed almost entirely out of carbon and hydrogen atoms, with a few oxygen atoms sprinkled in.

Now when your body exposes triglyceride to the oxygen you breathe in, that highly reactive oxygen starts breaking the triglyceride molecule apart. With each chemical bond that breaks, a little bit of energy is released (allowing you to keep exercising), and the broken pieces of triglyceride recombine with oxygen to make carbon dioxide (CO2) and water (H20).

It’s worth noting that chemical bonds do contribute marginally to the total mass of a molecule, so when you break them and turn them into energy, E = mc2 does apply, sort of. But that’s nowhere close to being a significant factor in terms of weight loss.

The vast majority of the weight you lose comes in the form of carbon dioxide, which you breathe out through your lungs, and water, which you sweat out or pee out or breathe out as water vapor. (If you want to get into the math and find out how many kilograms of oxygen you need to burn how many kilograms of triglyceride, producing how many kilograms of water and CO2, click here.)

When I started studying chemistry, this was not the kind of thing I was hoping to learn. I’m a science fiction writer. I’m interested in the type of chemistry that makes rocket engines go, or drives weather patterns on other worlds, or could make alien life possible.

But still, it’s exciting to me when I can connect all that outer space science to some of the mundane aspects of life here on Earth.

* * *

Today’s post is part of a special series here on Planet Pailly called Molecular Mondays.

On the first Monday of the month, we take a closer look at the atoms and molecules that make up our physical universe, both in reality and in science fiction.


Sciency Words: Basic

May 5, 2017

Today’s post is part of a special series here on Planet Pailly called Sciency Words. Each week, we take a closer look at an interesting science or science-related term to help us expand our scientific vocabularies together. Today’s term is:

BASIC

During this year’s A to Z Challenge, I ended up covering several scientific terms that do not mean what you might think they mean. Notable examples include reduction, metallicity, and volatile. Basic is another good example, but I already had something else I really wanted to do for B.

Whenever I hear someone talking about basic chemicals, it’s not always clear to me what they mean. On the one hand, basic could mean simple or ordinary.

But basic can also mean fundamental or foundational, as in a base is a foundation upon which you can build something. This gets us closer to what the word means (or should mean) whenever we’re talking about chemicals.

A “Base” for Salt

The modern usage of base and basic in chemistry can be traced back to the mid-1700’s, to Guillaume-François Rouelle, a French scientist who studied the chemical formation of salts. Rouelle found that certain substances, such as alkalis, served as good “bases” for creating salts.

All you have to do is take one of Rouelle’s bases, add an acid, and voilà! you have a salt. And if your base happens to be sodium hydroxide and your acid happens to be hydrochloric acid, you end up with water and sodium chloride, a.k.a.: table salt.

So the next time you run out of table salt but have plenty of sodium hydroxide and hydrochloric acid around, you know what to do!

A “Base” for Protons

Our understanding of acid-base chemistry is a little more sophisticated today than it was in the 1700’s. Rouelle wouldn’t have known about protons, for example. Fortunately, the original terminology still makes a certain sense, even after we learned of protons and the role they play in acid-base reactions.

In most cases (excluding Lewis acids and Lewis bases), an acid can be thought of as a molecule with a proton dangling loosely off the side. This dangling proton will break off at the first opportunity, so long as the proton can find a better place to go.

In this context (again, excluding Lewis acids and Lewis bases), a base can be thought of as a molecule that can accept a proton that has broken free of an acid. In other words, it’s the “base” upon which the proton can land and make a new home for itself.

Basic Chemicals Aren’t So Basic

So if you hear someone talking about basic chemicals, you might want to ask for some clarification. By “basic,” do they mean (wrongly) a common or easy-to-make chemical, or are they talking (in a more proper sense) about acid-base chemistry?


Molecular Monday: Why Chemistry?

May 1, 2017

The first Monday of the month is Molecular Monday here on Planet Pailly!

We just wrapped up this year’s A to Z Challenge, and I ended up writing a lot about chemistry. A lot more than I expected. You’d think I must really love chemistry.

But I don’t.

I really don’t.

For a long time, I tried to avoid the subject completely due to bad memories from high school chemistry. My professor was extremely generous in giving me a just-barely-passing grade.

So when I made the commitment to include more science in my science fiction, I figured I could get by with just the “fun” sciences like physics and astronomy. Then in 2015, I did my yearlong Mission to the Solar System, and the planet Venus forced me to start learning this chemistry stuff.

As you can see in this totally legit actual Hubble image, Venus has some very special chemical activity going on.

There’s simply no way to understand what’s happening on Venus without getting into the weird sulfur chemistry of the Venusian atmosphere. But once you do make sense of that sulfur chemistry, a strange new world is suddenly open to you: a world of both heavenly beauty and acid rain hellfire death.

Since my experiences with Venus, I’ve come to realize that understanding chemistry, even at a basic level, makes my work as a science blogger and science fiction writer so much easier.

  • Is there life on Mars or Europa? What about life in other star systems, or silicon-based life? If alien life is out there, it will be the product of chemistry.
  • What about humans traveling to other worlds? What would be safe for us to eat or breathe? Chemistry can help answer that too.
  • Venus isn’t the only world defined by chemistry. Earth has been shaped in large part by the chemistry of oxygen and water; the gas giants by ammonia and methane; and then there’s a true oddball like Titan with its tholen chemistry.
  • And how am I going to get my rocket ship off the ground? By mixing rocket fuel. In other words, by doing chemistry.

Chemistry is by no means the most fundamental science, but for the kinds of things I write, it is the most applicable science. So even though I don’t enjoy the subject, I’ve forced myself to stick with it.

And if I’m being perfectly honest, in those aha-moments when complex chemical reactions suddenly makes sense to me, I may quietly murmur to myself, “Okay, chemistry is kind of fun.”