Tag: Science

Pique the Geek 20121021: Reflections on the Genus Carya

Today was a splendid day in the Bluegrass.  The temperature was in the low 70s, only a very light breeze, and not a cloud in the sky.  The Woman had gone to birthday party for a relative, but when she got home I took over the pumpkin pie that we had baked together last night and we each had a piece.  The crust, described here, was perfect.

I left a generous portion of the pie, and she gave me a big hunk of the pumpkin roll that we also made last night.  I knew that she was going to be busy later in the day, so I went nutting.  My target today was hickory nuts, getting ready for holiday baking.  There is a tree that is a reliable cropper just about half a mile from my house, in the yard of some very nice people who always tell me to get as many nuts as I care to pick up, and so I did.  Within an hour I had enough clean nuts for all of the holiday cooking, and then some.

Pique the Geek 20121007: More about Sodium

Last time we started our discussion about sodium, and tonight we shall continue it.  We have pretty much covered the quantum mechanical part and the properties and uses of elemental sodium, so tonight we shall focus on some of the compounds of that element.

Sodium compounds are extremely common and widespread, but not universally distributed.  This is important for reasons to be seen later.

The most common sodium compound is common salt, or sodium chloride, NaCl.  Everyone has personal experience with salt, both as a nutrient and as a melting aid for icy surfaces.

Pique the Geek 20120930: Sodium — You Can Not Get Away from It

Sodium, element number 11, is one of the most common elements in the crust of the earth.  Except for school laboratory demonstrations, few people have ever seen elemental (metallic) sodium because it is so reactive and actually has very limited consumer uses (that would be about zero consumer uses).

We have hinted at the concept of periodicity previously, like last week when we saw how similar the chemical behavior of helium and neon are.  The similarities betwixt hydrogen and lithium are much less marked than those betwixt lithium and sodium, mostly due to the extreme low mass of hydrogen, making quantum effects more pronounced.  Thus, sodium is the second alkali metal after lithium even though hydrogen is in the same column in the periodic table.

In other words, the two first row elements, hydrogen and helium, are aberrant because of their low masses AND because they have only the K electron shell in the ground state AND as a corollary, only the 1s orbital that is filled with only two electrons.  Starting with the second row, the L shell begins to be filled and it contains, in addition to the 1s orbital, a 2s and three 2p orbitals.  Row three elements, sodium being the first of which, also contain in addition to those orbitals, a 3s and three 3p orbitals, making them more like the second row than the second is to the first row.

The Harvest Moon Meets Uranus

Watch Live: Harvest Moon Meets Up With Uranus in Opposition

An odd pair of solar system objects will be meeting up in the night sky tonight: the full moon and distant Uranus. You’ve got two opportunities to watch this sweet celestial action go down during two live Slooh Space Camera shows, the first at 4 p.m. Pacific/7 p.m. Eastern and the second at 7 p.m. Pacific/10 p.m. Eastern on Sept. 29. [..]

This weekend’s full moon will be known as the Harvest Moon, since it occurs nearest to the autumn equinox. Uranus will be in opposition to Earth, meaning it will be as close and bright as it can be in the night sky, and will be nearly perfectly lined up with the moon. Amateur astronomers can get a good glimpse at Uranus by aiming just below the moon and searching for the only green star in their field of view.

The Slooh show will be hosted by Patrick Paolucci, who will be joined by Bob Berman, columnist for Astronomy magazine.

Harvest Moon and Uranus Show #1

h/t Adam Mann at Wired Science

Pique the Geek 20120923: Neon, as Inert as Elements Come

Last time we talked about fluorine, the very most reactive chemical element.  Now we add a single proton to the fluorine nucleus and come to Element 10, the LEAST reactive chemical element.  What a difference a charge can make!

Actually, neon is quite common in the cosmos but quite rare on earth.  It is fifth, after the elements that we have already discussed, because it is mostly a light even/even nucleus.  But that is not what makes it outstanding.

There are three stable isotopes of neon, 20Ne, at almost 91% natural abundance on earth, 21Ne, at about a quarter on one per cent, and 22Ne, the remainder.  This gets important later.

Pique the Geek 20120916: Fluorine, Something You Have Never Seen

Element 9, fluorine, is the first of the halogens, from the Greek halos, “salt”, and gonos, “to bring forth”.  All of the members of this family tend to form salts with metals, but fluorine is unique amongst the halogens in that it forms compounds with EVERY element ever tried except for helium and neon.

Fluorine is by far the most reactive element, having everything just right for extreme chemical behavior.  It is a small atom that forms a small ion.  Its electrons are tightly bound in its ionic form, but oddly molecular fluorine has a remarkably weak bond for a halogen, only iodine having a weaker one.

The element has been known in the form of naturally occurring salts since the Middle Ages, when these minerals were used as fluxes in metal smelting.  The purpose of a flux is to make the ore and reducing agent mixture easier to melt, thus speeding the reaction since liquid state reactions occur much faster than solid state ones.  A secondary use of a flux is to protect the newly won metal from atmospheric oxygen by forming a protective layer that floats on the metal.

Pique the Geek 20120909: Oxygen Wrapup

Last time we discussed oxygen as an element, including why we do not burst into flame in our 21% oxygen atmosphere.  Quantum mechanics can really be interesting.

This time we shall discuss some of the compounds of oxygen with other elements, and I emphasize SOME because oxygen forms hundreds of thousands if not millions of compounds.

Some of these compounds are essential industrial materials, some are essential for biological processes, and some of them can cause real problems when released into the atmosphere.  A few of them are quite toxic.  Let us look into them!

Pique the Geek 20120902: Why we do not burst into flame — Oxygen

Oxygen is one of the most fascinating elements for many reasons.  Before we get to it, I first want to point out that the column of the periodic table that starts with nitrogen are called pnictogens, whislt the column starting with oxygen are called chalcogens.  The term pnictogen is recent, dating form the 1950s.  It comes from the Greek plural noun pnikta which means something on the order of “those that are suffocated” in reference to the fact that nitrogen will not support life.  The “gen” part is from the Greek gonos, “born” or “generated”.

Chalcogen comes from the ancient Greek chalkos, meaning “ore” and gonos, and in fact an extremely large number of metal ores contain oxygen or sulfur of both.  Selenium and tellurium are chalcogens that are often found in gold and silver ores.

Time before last we discussed nitrogen and molecular orbital diagrams for it.  If you are not hip to MO diagrams, I suggest you read that part of the link before you try to tackle the MO diagrams for oxygen.

Pique the Geek 20120826: Nitrogen, Extremely Versatile

Last time we talked about the unusual properties of elemental nitrogen mostly and how stable it is.  We only touched on a little of the fascinating and extremely complex chemistry of nitrogen, ONCE we can get it in a form other than the incredibly stable elemental form.

This time we shall remedy this, although entire graduate level texts have been written on the subject.  Tonight we shall take a brief survey of the impact that nitrogen has on living organisms, industry, and a few other areas.  We shall attempt to do this by looking at various oxidation states, and nitrogen has more than any other element.

The basic concept is that atoms can either donate or accept electrons from other atoms.  When an atom donates electrons, it is oxidized, and when it accepts electrons it is reduced.  Thus, chlorine bleach works because hypochlorite ion is a strong oxidizing agent and breaks up large, colored molecules to smaller, colorless ones.

Pique the Geek 20120819: Nitrogen, without Life?

I took a week off from blogging last week for a number of reasons.  One was that I was having trouble getting my mind around topics.  Another was being in sort of a strange set of moods that have made concentration rather difficult.  Yet again, and probably the root cause of the other two is either spending large amounts of time with someone (no time to write) or no time at all (no motivation to write).  In any event, I think that I have some balance back.

I got tired of writing about carbon so we shall move on to nitrogen.  With an atomic number (Z) of 7, it is the element after carbon.  Nitrogen is another of the few elements that ordinary people encounter on a daily basis, because it comprises around 78% of the atmosphere of the earth.

There are two stable isotopes of nitrogen, the very common 14N (99.64%), the rest being 15N.  Both of these isotopes are formed in larger stars by stellar nucleosynthesis.  Nitrogen is peculiar in that it is one of only five nucleides that are stable with both an odd number of protons and neutrons.  It is really unusual in that 14N is by far the most common isotope of nitrogen.

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