Gaseous Nobility

Every day I receive an e-mail from a site called delancyplace.com. Each e-mail contains a short excerpt from a book, mostly books concerning science or history. They are well-chosen excerpts and I enjoy most of them. If you would like to sign up (it’s a free service) here’s the link:

Delancyplace

Here’s an example I received today; I thought it was very well-written:

In today’s excerpt – the Noble Gases, also known as inert
gases, are located in column eighteen on the far right side
of the Periodic Table of Elements and consist of: Helium
(He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and
Radon (Rn).  Each of these gases, under standard
conditions, are odorless, colorless, monatomic gases, with
very low chemical reactivity: 
 
Noble is an archaic word, less chemistry than ethics or 
philoso­phy. And indeed, the term ‘noble gases’ goes back 
to the birth­place of Western philosophy, ancient Greece. 
There, after his fellow Greeks Leucippus and Democritus
invented the idea of atoms, Plato minted the word “elements” 
(in Greek, stoicheia) as a general term for different small 
particles of matter. Plato­ – who left Athens for his own 
safety after the death of his mentor, Socrates, around 400 
BC and wandered around writing philoso­phy for years – of 
course lacked knowledge of what an element really is in 
chemistry terms. But if he had known, he no doubt would 
have selected the elements on the eastern edge of the table, 
especially helium, as his favorites.  In his dialogue on 
love and the erotic, The Symposium, Plato claimed that every 
being longs to find its complement, its miss­ing half. When 
applied to people, this implies passion and sex and all the 
troubles that accompany passion and sex.  In addi­tion, Plato
emphasized throughout his dialogues that abstract and
unchanging things are intrinsically more noble than things
that grub around and interact with gross matter. 

Helium is also the best example of ‘element-ness’ – a 
substance that cannot be broken down or altered by normal, 
chemical means. It took scientists 2,200 years, from Greece 
in 400 BC to Europe in 1800 AD, to grasp what elements 
really are, because most are too changeable. It was hard to 
see what made carbon carbon when it appeared in thousands of
compounds, all with different properties. Today we would
say that carbon dioxide, for instance, isn’t an element
because one molecule of it divides into carbon and
oxygen. But carbon and oxygen are elements because you
cannot divide them more finely without destroying
them. Returning to the theme of The Symposium and Plato’s
theory of erotic longing for a missing half, we find that
virtually every element seeks out other atoms to form bonds
with, bonds that mask its nature. Even most “pure”
elements, such as oxygen molecules in the air (02) always
appear as com­posites in nature. Yet scientists might have
figured out what elements are much sooner had they known
about helium, which has never reacted with another
substance, has never been any­thing but a pure element.

Helium acts this way for a reason. All atoms contain
nega­tive particles called electrons, which reside in
different tiers, or energy levels, inside the atom.  The
levels are nested concentrically inside each other, and
each level needs a certain num­ber of electrons to fill
itself and feel satisfied. In the innermost level, that
number is two. In other levels, it’s usually eight. 
Ele­ments normally have equal numbers of negative
electrons and positive particles called protons, so they’re
electrically neutral. Electrons, however, can be freely
traded between atoms, and when atoms lose or gain
electrons, they form charged atoms called ions.  

What’s important to know is that atoms fill their inner,
lower-energy levels as full as possible with their own
elec­trons, then either shed, share, or steal electrons to
secure the right number in the outermost level. Some
elements share or trade electrons diplomatically, while
others act very, very nasty. That’s half of chemistry in
one sentence: atoms that don’t have enough electrons in the
outer level will fight, barter, beg, make and break
alliances, or do whatever they must to get the right
number. 

Helium, element two, has exactly the number of
electrons it needs to fill its only level. This “closed”
configuration gives helium tremendous independence, because
it doesn’t need to interact with other atoms or share or
steal electrons to feel satis­fied. Helium has found its
erotic complement in itself. What’s more, that same
configuration extends down the entire eigh­teenth column
beneath helium – the gases neon, argon, krypton, xenon, and
radon. All these elements have closed shells with full
complements of electrons, so none of them reacts with
anything under normal conditions. That’s why, despite all
the fervid activ­ity to identify and label elements in the
1800s-including the development of the periodic table
itself-no one isolated a sin­gle gas from column eighteen
before 1895. That aloofness from everyday experience, so
like his ideal spheres and triangles, would have charmed
Plato. And it was that sense the scientists who dis­covered
helium and its brethren on earth were trying to evoke with
the name ‘noble gases.’ Or to put it in Plato-like words,
“He who adores the perfect and unchangeable and scorns the
corruptible and ignoble will prefer the noble gases, by
far, to all other elements. For they never vary, never
waver, never pander to other elements like hoi polloi
offering cheap wares in the marketplace. They are
incorruptible and ideal."

The repose of the noble gases is rare, however. One col­umn
to the west sits the most energetic and reactive gases on
the periodic table, the halogens. And if you think of the
table wrapping around like a Mercator map, so that east
meets west and column eighteen meets column one, even more
violent ele­ments appear on the western edge, the alkali
metals. The pacifist noble gases are a demilitarized zone
surrounded by unstable neighbors.

Author: Sam Kean

Title:The Disappearing Spoon

Publisher: Back Bay Book, Little Brown and Company

Date: Copyright 2011 by Sam Kean

Pages: 15-17

Here’s a representation of the Periodic Table. The noble gases are in the light-blue column at the far right:

Larry

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