Tag Archives: chemistry

Elemental Relationships

Niobium is a silver grey metal that holds number 41 on the periodic table. It sits just above tantalum, number 73.

Besides both being silver-grey transition metals vital to modern technologies they have a classical as well as elemental relationship. In Greek Mythology Tantalus was Niobe’s father.

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Clair Patterson, Rocks from Space, and Metal in the Air

It’s not a secret that I’ve got a soft spot for meteorites, especially the sort that I can get my hands on and turn into jewelry.

 

Since meteorites are samples of the universe outside our atmosphere they are kind of by definition awesome, excepting the occasional mass extinction event causation. But humans are knowingly creating the current age of mass extinction, so who are we to throw stones at non-sentient space rocks?

 

Clair Patterson

A scientist named Clair Patterson (1922-1995) used meteorites to help determine the age of the earth. In studying them to learn about our home, he discovered a much closer and more personal problem-atmospheric lead.

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Elemental Creatures

 A little bit more periodic trivia for you. Two of the elements on the periodic get their names from folkloric creatures. (cue Peer Gynt)

Cobalt (element 27) is not found on its own in nature, only in mineral ores.

We use it now in steel alloys to make tougher drill bits and milling machine parts.

It has been used unknowingly since ancient times to color paint and glass. The ancient Egyptians used it along with iron and copper to get lapis blue glass. It’s also been found in blue and white Chinese porcelains from the 8th or 9th centuries. So it’s been around, just hiding out of sight under the blues. It creates a stable pigment that was once attributed to the element bismuth. (Cobalt blue wasn’t actually called cobalt blue until 1777.)

Maxfield Parrish, Reveries. (With cobalt blue.)

Chemistry and quilting, I’d love to see the finished project!

The artist Maxfield Parrish used cobalt blue in his rich, luminous skyscapes- some people call cobalt blue Parrish blue thinking of his skies. (I admit that I tend to do it, especially when looking at the outline of dark trees against a rich sky. Parrish just comes to mind first.)

Don’t be too distracted by the color.

Cobalt is needed for life in minute quantities but in a larger volume can be poisonous. People grinding the pigment had to be careful not to breathe it in, and when the ore was first found it was called kobald ore, German for goblin or sprite ore, because it was so problematic. It looked like silver ore but seemed to be poor in metal and gave off poisonous fumes containing arsenic when smelted. Cobalt itself was finally isolated in the 1730s and named after the troublemaking kobalds.

Kobalds are creatures from Germanic folklore. No one seems to agree on where they (myth or creature) come from originally. The stories go back at least to the 13th century and may be vestiges of Nordic mythology. The underground kobalds blamed for the evil temper of the ore seem to be folkloric cousins to knockers and bluecaps. They’re normally imagined as child sized old men, sometimes otherwise normal and sometimes as hunched over and ugly.

Cobalt’s neighbor on the periodic table, Nickel (element 28) is also named after a troublemaker.

In medieval Germany miners found reddish ore with a green crust that looked like copper ore, but from which they couldn’t get any copper. They blamed the Nickel (word history issue alert: some sources say it’s as in Old Nick or the Devil and others translate it as a term for goblin) for their trouble, and called the ore Kupfernickel. In the 1700s the chemist studying the ore got an unknown white metal which he named after the troublesome spirit.

Hall of the Mountain King

At first kupfernickel was the only source of nickel, but luckily other sources had been found by the time it was in demand for steel production at the end of the 19th century. Today nickel-iron alloys are used in the hottest parts of jet engines because they stay strong even in intense heat.

The first thing most people in the US think of when they hear nickel is $.05. Nickel has been used in minting coins from different countries since the start of the 19th century. It’s gotten too expensive to use much in coinage any more, and the US is one of the few countries that still has a fair amount of nickel in lower denomination coins. The nickel used in making a nickel coin is worth about 90% of the coin’s face value. (Normally the metal is worth far less-old pennies are the big exception. Nickel’s other neighbor, copper, is worth enough that the old copper pennies from before 1982 are worth over twice their face cost in metal!)

Nickel can still be a problem. A lot of people are touch sensitive to it and can get red and itchy skin from contact. Because of its resistance to corrosion, it used to be used in jewelry intended for pierced ears. (It’s nickel that helps put the stainless in stainless steel.)

Most of Earth’s nickel is in our planet’s inner and outer cores. Like cobalt, nickel is mostly found in its native state in meteoric iron. Which is in itself possibly a good example of our core’s composition.

I’ll confess, I don’t generally work with any metals containing nickel, but I make an exception for meteorites! As I’d mentioned with meteorites before, the nickel in iron-nickel meteorites helps keep them stable and usable. P1110545-edit-blog

Another fun fact about these elemental neighbors and their matching names-the chemist who discovered nickel (Axel Cronstedt) was a student of George Brandt, who discovered cobalt. So student and teacher’s discoveries sit next to each other on the periodic table, and both elements are named after the creatures blamed for the miners’ frustrations!

They even caused frustration for chemists later on. Most elements get heavier as you move across the periodic table from left to right. In the 1860s this was considered one of the universal laws of nature, but laws don’t have exceptions and cobalt is slightly heavier than nickel! Theoretical and experimental chemists bickered for years over a few pair weight reversals in the periodic table.

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A Harvest Tangent

 The other day someone mentioned the thirteen planets, and it gave me pause, since I thought there were less than when I was little, not more.

 

Oops. I didn’t realize all the dwarf planets had been named. Obviously I knew Pluto, and Eris sounded familiar, Ceres I thought was a large asteroid, and I didn’t remember Haumea or Makemake. I thought it was a good time of year to take a quick look at Ceres.

 

Ceres was the Roman goddess of agriculture, grain, fertility and motherhood. She’s essentially the Roman version of the Greek goddess Demeter. Linguists aren’t sure where the name Ceres comes from, one theory is that it shares a lost indo-European root with create, kernel, increase, corn, etc. We get the word cereal from her name.

 

 She was credited with discovering wheat (spelt) and with yoking oxen for plowing. Her main festival was held in spring, but now fall seems the appropriate time to visit the myths. The Romans saw her as connected to the line between life and death. She had a personal connection to the dead once the Romans nabbed Persephone from the Greeks and named her Proserpina.

 

In 1801 a newly discovered planet was named after her. It was first discovered on January 1, observed two dozen times, lost, then finally independently confirmed on December 31rst. (Perhaps Janus would have been a better name…) It has fluctuated between asteroid and planet and now seems to be considered both a dwarf planet and an asteroid.

 

Ceres is the only dwarf planet in the inner solar system. It lies in the asteroid belt between Mars and Jupiter. Even at its brightest it is too dim to see with the naked eye except in the darkest, clearest skies. When he first saw it, its discoverer wasn’t sure if it was a comet or planet, but it seemed to be too stable for a comet.

 

Ceres is about 600 miles in diameter, about the size of Texas.

 

 I wasn’t sure if the dwarf planet designation was all about size.

 

There seems to be a little more to it than that. Planet is a cultural and not a scientific designation, so the whole thing is sort of vague. The 2006 dwarf planet description is basically a spherical object in a more or less regular orbit around the sun that isn’t large enough for its gravity to have cleared its orbit of most other celestial bodies. (So too small to enlarge itself by eating all its neighbors.)

 

What’s cool is in March 2015 (scary how not far away that is) NASA’s Dawn mission will be studying the structure of Ceres and a nearby asteroid, Vesta, to see how they were formed. They think these small bodies have altered less in the past 4.6 billion years than the planets have, since Jupiter’s gravity both protects them and stopped them from forming a planet.

 

 

chemistry http://periodictable.com/Elements/058/index.html

Photograph of Cerium from Theo Gray’s wonderful book on the elements.

 The element cerium (58) was discovered in 1803, and named after the recently discovered planet.

 

It is the most common (and least expensive) of the rare earth elements. It’s nearly as common as copper, the rare earth elements are named less for their scarcity than for the trouble it takes to isolate them. Cerium is a soft silvery metal that can catch fire when it is struck. The whole piece won’t burn, but any bits knocked off burn as they’re made. So cerium is used in lighter flints and in special effects where lots of sparks are needed.

 

At high temperatures (65-80 degrees Celsius) it can ignite spontaneously in air. Its fumes are toxic and you can’t douse it with water since cerium will react with water ot product hydrogen gas. So as much fun as it sounds like to play with, it sounds like an element to avoid unless you have the training.

 

The Greeks sometimes call cerium dimitrio, after Demeter.

 

Okay, so it’s a dwarf planet and a rare earth element named after her second hand, but still not bad for a goddess mostly defunct for centuries!

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Dreidels and Chemistry

Honestly it’s only a one word connection, but it sticks for some reason.

 

So trivia for you: gadolinium (Gd, element 64) is the only element in the periodic table with a Hebrew etymology.

 

Gadol means great in Hebrew.

 

You see it in nes gadol haya sham meaning a great miracle happened there, this time of year. It’s a reference to the story of Chanukah, and dreidels have the first letter of each word on their sides. (Those same letters are also used to stand for whether you take or put into the pot when gambling with dreidels.)

 

Dreidel as a gambling game has roots in European history. Apparently it’s a riff off of an old Irish and English game called teetotum, and the terms for dreidel are Yiddish, a hybrid of Hebrew and German.

 

There’s some debate over whether the Hebrew letters on a dreidel (Nun, gumel, hei, shin) were there first in reference to the rules of the game and the Chanukah meaning added after, or if the game rules were tailored to fit the acronym celebrating Chanukah. I’ve seen arguments both ways and don’t have the background to make a call on it!

 

Gadolinium is one of the Lanthanides (f-block elements) naturally occurring rare earth metals. In nature it is only found in salt form. (Bonded to other elements.)

When separated it is a silver-white heavy metal. It’s useful in metallurgy since even a small amount improves the workability or iron alloys. It is also good at absorbing stray neutrons and so is used in radiography and nuclear reactors.

 

One of gadolinium’s main uses is in compounds for MRIs. Injected into the bloodstream, it will show where blood is and is not in a scan, which helps pinpoint the location of blocked or leaking blood vessels.

 

What’s really cool (and kind of mind bending, at least to me) is that it goes from being magnetic to not, depending on its temperature. This is called the Curie point, and in gadolinium it’s 19 degrees C (66 F). So if you use ice water to cool down gadolinium it will stick to a magnet, only to fall off once it warms up again.

 

It gets its name from the mineral gadolinite. A chemist studying gadolinite saw an unknown spectral band and identified an new element. (He actually had to use a different mineral with a larger gadolinium content to extract an oxide of gadolinium.)

 

Later a French chemist, P.E.F. LeCoq, separated metal from oxide and (since there’d already been a hullabaloo about his possibly naming his previous find after himself-he’s a piece of work, maybe we’ll talk about him later) he named this new element after the mineral in which it had first been identified.

 

This mineral had been named after Johan Gadolin. (b 1760)

 

Describing Gadolin as the everyman of the elements: “Gadolinium must stand as the memorial for all the chemists who have struggled to free a new element from its mineral source…” Hugh Aldersey-Williams, Periodic Tales.

 

Johan Gadolin was the chemist who discovered the first rare earth element- yttrium. (Well, first rare earth oxide, he knew it has a new element in 1794 but couldn’t extract it.) The mineral from which he isolated yttrium was named Gadolinite in his honor.

 

So the element was named after the mineral which was named after him for extracting a different element from said mineral. It’s kind of a nice naming circle!

 

Where does the Hebrew come in?

 

Clerical families often took a Latinized name. Instead of looking at Latin roots, Gadolin’s grandfather gentrified their family name by taking the Hebrew word for great and modifying it to fit with Latin forms.

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An emerald, how beautiful!

May’s traditional birthstone is emerald. It seems like a wonderful option for the northern hemisphere, rich green just as the buds are unfurling into proper leaves.

Emerald is a type of beryl. (From aluminum beryllium silicate.) The word itself comes from the Greek for green stone, and probably did originally refer to most green stones. The stone has been known since ancient times, the Greeks and Romans used them and made fakes out of glass, as did the Egyptians. Cleopatra was said to have emerald mines among her vast wealth. (And there is some evidence that that is truth rather than rumor.) Probably the most beautiful emeralds I’ve ever seen were in ancient jewelry in the British Museum. I later years the Spanish plundered large quantities of emeralds from the New World as well as their hauls of gold and silver.

The trace elements chrome and vanadium both make beryls green, but traditionally only beryls colored green through traces of chrome are considered emeralds. Gemologists are still debating if a vanadium green beryl is a true emerald. (The authors of my assorted books all disagree with each other as well. It sounds like there isn’t an official decision if gems are to be classified by color or by chemistry.) Emeralds are one of the few precious stones where inclusions are expected, a too clear gem is considered suspect. Inclusions are euphemistically called jardin– french for garden- reflecting the shape combined with the color of the stone. (Probably my favorite euphemism for flaws…) Some translucency is a plus, and the deeper greens with a hint of blue are the most valuable.

The classic emerald cut was designed to reduce the fragile spots on the stone, since they are sensitive to knocks.

A movie moment in honor of emeralds and their fascinating color. Gigi learns about jewelry from her aunt, and to look for that hint of blue that makes an emerald so stunning. (And also a nod to Mother’s Day. The ‘topaz, among my jewels, are you mad’ line is a running joke with my mother…)

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Spoon!

Fine gold wire around a crytal formed from a single element. (element 83) Kean explains how Bismuth forms its escheresque shape in his book.

This summer I read a great book by Sam Kean called The Disappearing Spoon.

It was essentially an introduction to/history of the periodic table, with digressions for fun facts and quirky personalities along the way. I’ve already reread it once. His writing is very good and his explanations clear. The title of the book comes from a trick he describes, where students mold gallium, which is a silver metal with an extremely low melting point, into the shape of a spoon and bring it with tea. The unsuspecting victim goes ot stir the tea, and the spoon melts. I kept meaning to look that trick up and forgetting about it. Then I ran across this video, which warmed my little geek heart.

And since we’re playing with the periodic table:

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