Sciency Words: Volatile (An A to Z Challenge Post)

April 26, 2017

Today’s post is a special A to Z Challenge edition of Sciency Words, an ongoing series here on Planet Pailly where we take a look at some interesting science or science related term so we can all expand our scientific vocabularies together. In today’s post, V is for:

VOLATILE

Whenever I hear somebody talk about volatile chemicals, I’m never quite sure what they mean. This is another case of a word that means one thing to the general public and something rather different to professional scientists.

In chemistry, a volatile chemical—also refered to simply as “a volatile”—is a chemical substance that tends to evaporate spontaneously under ordinary temperature/pressure conditions. A common example of a volatile here on Earth is water.

Of course you may encounter other chemicals here on Earth far more volatile than water. Just think about alcohol or gasoline. You might also think about nitrogen, oxygen, or hydrogen, because if you manage to get these chemicals into their liquid phases, they will immediately turn back into gases at the first opportunity. That makes them extremely volatile.

To be clear, the volatility of a chemical has nothing to do with how flammable, explosive, reactive, or unstable it is. That may seem a little confusing, but unlike previous confusing chemistry terms we’ve seen (like organic or reduction), I’m not sure I can fault chemists for this one. The chemistry definition is actually closer to the original meaning of the word; in a sense, it’s the rest of us who’ve been using the word wrong.

When volatile first entered the English language from French, it could mean either “light weight” or “evaporating quickly.” The “violent and unpredictable” meaning didn’t come until later. If you go further back into the word’s history, you find it derives from a Latin word meaning “to fly away,” which is actually an apt description of what atoms and molecules do when a volatile chemical evaporates.

Next time on Sciency Words: A to Z, the WIMPs will take on the MACHOs. Which acronym will win?


Sciency Words: Reduction (An A to Z Challenge Post)

April 21, 2017

Today’s post is a special A to Z Challenge edition of Sciency Words, an ongoing series here on Planet Pailly where we take a look at some interesting science or science related term so we can all expand our scientific vocabularies together. In today’s post, R is for:

REDUCTION

In his book Atom: Journey Across the Subatomic Cosmos, Isaac Asimov writes:

It often happens that a poor name is given to an object or a phenomenon to begin with, either out of ignorance or out of bad judgment. Sometimes, it can be changed in time, but often the ill-chosen name is used so commonly by so many that it becomes inconvenient or even impossible to change it.

Hank Green says much the same thing at the beginning of this episode of Crash Course: Chemistry on oxidation and reduction.

I wish someone had told me this in high school chemistry, because I could never make sense out of reduction. The name confused me too much, because it means the opposite of what it should mean.

Some atoms are naturally greedy for electrons. These atoms are called oxidants.

And some atoms are naturally well inclined to give electrons away. These atoms are called reductants.

When a reductant gives an electron to an oxidant, the reductant is said to have been oxidized. And when an oxidant gains an electron from a reductant, the oxidant is said to have been reduced.

Yes. The gaining of an electron is called reduction, a word typically associated with the losing of something. Just… how even? This is one of the most fundamental reactions in all of chemistry. No wonder chemistry is so notoriously hard!

Apparently long ago, it was observed that some substances become lighter after undergoing a chemical reaction. Hence, reduction. We now know the substances in question were gaining electrons (which weigh practically nothing), while incidentally losing other, heavier things in the form of gases. But how were scientists of the 18th Century supposed to know that?

We can take some consolation in the fact that when a chemical substance gains electrons, its oxidation number goes down. So in that sense, the word reduction doesn’t seem completely stupid.

But Asimov and Green hit upon a key insight on how scientific terminology works—or rather, why it doesn’t always work. When you really delve into the scientific lexicon, you find this naming before understanding trend everywhere. As a result, we’re now stuck with a ton of confusing, counterintuitive names for important scientific concepts.

Next time on Sciency Words: A to Z, we’ll jump feet first into a black hole.


Sciency Words: Organic (An A to Z Challenge Post)

April 18, 2017

Today’s post is a special A to Z Challenge edition of Sciency Words, an ongoing series here on Planet Pailly where we take a look at some interesting science or science related term so we can all expand our scientific vocabularies together. In today’s post, O is for:

ORGANIC

Sometimes scientists name things before they fully understand them. Such is the case with the entire field of organic chemistry.

Organic chemicals are called organic because, it was once thought, they could only be produced by living organisms. There was something almost mystical, almost magical about living things, scientists believed. They spoke of a mysterious “vital energy” without which certain chemical reactions simply could not occur.

Then in 1828, Friedrich Wöhler synthesized urea–a key ingredient in urine–in a test tube. That sounds kind of gross, but it was a monumental achievement in the history of science.

Sort of like how Newton showed that the same laws of physics which apply here on Earth also apply to the planets and stars, Wöhler’s urea synthesis demonstrated that the same laws of chemistry apply to both living and non-living matter.

The group of chemicals that scientists had been calling “organic” do have at least one thing in common: carbon. They all incorporate carbons atoms, typically carbon atoms bonded to other carbon atoms or to hydrogen atoms (certain simple carbon compounds like CO2 are generally not considered organic).

Perhaps some other name would be more appropriate for these complex carbon molecules, but scientists had been calling them organic chemicals and talking about organic chemistry for a while. The name had already stuck.

I suppose we could rationalize the modern usage of organic by saying we organisms need organic chemicals to live; but thanks to Wöhler, we now know organic chemicals do not need us organisms in order to exist.

Next time on Sciency Words: A to Z, let’s see if we can get Pluto’s planet status back.