Technology Archives - Page 2 of 4

18Apr 2019 by Vincent Summers 1 Comment

Cyclosilicates: Beautiful Gemstones of Technological Interest

[caption id="attachment_23902" align="alignright" width="440"] Aquamarine cyclosilicate. Image by Vassil[/caption] Straight-chain silicates are common in nature. The anionic or negative portion of the silicates consists of silicon and oxygen, sometimes in conjunction with metals Thus there are aluminosilicates, magnesium silicates, and ferrosilicates. Sodium silicate, one of the most common examples, is simply, Na2SiO3. In its anhydrous form, sodium silicate adopts a tetrahedrally-linked polymeric form. Most silicates are not cyclic. Yet, the most beautiful silicates in the world – the most beautiful gemstones – are cyclosilicates. Interestingly, it is the technological beauty of these silicates that has been turning heads. It may be that the most beautiful thing about cyclosilicates is their hole. What Are Cyclosilicates? Cyclosilicates have the same tetrahedral linkage as other silicates, but in their case, the chain ends…

15Apr 2019 by Vincent Summers 19 Comments

Rare Earth Metals – 17 Special Elements

Chemistry, Technology

[caption id="attachment_23646" align="alignright" width="480"] Rare Earths. Photo ARS-USDA by Peggy Grubb.[/caption] Most of us are familiar with elements – the building blocks of matter. Most of us know about elements such as oxygen, nitrogen, carbon, sulfur, sodium, and helium. Yet, there are other elements few have even heard of, despite their immense technological and medical importance. Are you familiar with the rare earth metals? Allow me to introduce them: what are they good for, and where do they come from? Rare Earth Metals Among the less commonly known elements are the rare earth metals. These elements have many important uses, such as: Rare earth metals are used in heat-resistant, powerful, permanent magnets. They are employed in superconductors for cryogenics applications. They are used in pyrophoric alloys for initiating combustion. And…

30Mar 2019 by Vincent Summers No Comments

Chemical Explosives: Picric Acid and Picrates

Chemistry, Technology

Two common varieties of reaction are acid-base and oxidation-reduction (Redox). A typical acid-base reaction involves the conversion of the reactants (naturally, an acid and a base) into a salt plus water. We all are familiar with table salt, which is only one of many salts. Table salt can be made by reacting hydrochloric acid with the strong base sodium hydroxide: HCl + NaOH → NaCl + H2O The valence states of the reactants remain the same when they are transformed into the products. Hydrogen, chlorine, sodium, and hydrogen all stay at +1, while oxygen remains at -2. Oxidation-Reduction Oxidation-reduction reactions feature valence changes. For instance, consider the oxidation of carbon by oxygen... C + O2 → CO2 Each carbon atom (left of the reaction arrow) loses 4 electrons, while each…

26Dec 2018 by Vincent Summers 8 Comments

The Tragic Case of the Los Angeles Wannabe Chemist

Chemistry, Technology

I wrote how I was, in younger years, badly gassed by the carcinogenic, heavy-metal compound chromyl chloride during a home chemistry experiment. Another article I wrote was about how I mistakenly produced, not an organic ester as intended, but a powerful tear gas. In both cases, I aptly demonstrated my lack of knowledge as a wannabe chemist. My "unfortunate" experiments did not prove tragic. Another fellow was not so fortunate... In fact, his experiment cost him – and sixteen others – their lives. Not to mention, those badly injured, and the many surrounding buildings it destroyed. Introducing Wannabe Chemist Bobby Magee Does the name remind you of the Janis Joplin song Me and Bobby Magee? Well our Bobby, or more precisely, Robert M. Magee was the son of James W.…

23Nov 2018 by Vincent Summers 3 Comments

Microwave Cooking Hot and Cold Spots – Why?

Food, Technology

You place your dinner of leftovers in a bowl in the microwave oven, loosely cover it, shut the door and set the timer for 6 minutes. You picked that time from experience. When the timer beeps, you pick up the plate with your oven mitt and set it on the table. Then you gingerly remove the covering to avoid a steam burn. You salt and pepper your food, let it set two minutes or so, and begin eating. You taste the first mouthful and it is perfect. However, the second mouthful much hotter! Stirring the food half-way through the cooking process would have helped prevent this. Why the Hot Spots? The oven is a microwave oven. The heat results from absorbed invisible waves, specifically microwave standing waves, produced by a…

26Aug 2018 by Vincent Summers 2 Comments

I Discover a 1935 U.S. Coast and Geodetic Survey Benchmark

Geology, Technology

I travel the county quite a bit, meeting and talking with people. Since my conversation is varied, I naturally receive all kinds of responses. One day, a man who is a bit of a recluse drew my attention to an artifact at the edge of the property. He told me that if anyone was to dig it up, including himself, he would get into trouble with the Federal Government! Naturally, I was intrigued. What was this artifact? The Unobtrusive Artifact The man pointed to a small concrete-filled pipe, rusted on the outside, that stuck up from the ground only a very little distance. In the middle of the smoothed concrete top was a little disk, imprinted with words in a circular fashion, much like a large coin. The words read:…

13Aug 2018 by Vincent Summers 1 Comment

Uranocene – The Trend Setting Aromatic Actinide Sandwich Compound

Chemistry, Technology

Uranocene, U(C₈H₈)₂, or biscyclooctatetraenyl uranium, is a most interesting aromatic organometallic sandwich compound.1 Notice its dumbbell-like shape. By no means is its shape uranocene's only claim to fame. But before we get into that, it would be helpful to explain terms. We can guess why it's an organometallic compound, just as we can guess why it's called a sandwich compound. Let us, however, discuss what we mean by the term aromatic. Aromaticity in a Nutshell An aromatic structure is a molecule or ion that is cyclic and flat and that incorporates 4n+2 conjugated (alternating) sp2 (double) bonds, where n is some small integer. It displays increased stability over non-aromatic structures. Despite possessing double bonds, aromatic structures tend to undergo substitution rather than addition reactions. It requires considerable energy to disrupt…

08Jun 2018 by Vincent Summers No Comments

The Fascinating Acetylacetone Molecule and Its Acetylacetonate Salts

Chemistry, Technology

[caption id="attachment_20255" align="alignright" width="400"] Cobalt III Acetylacetonate[/caption] Acetylacetone is the simplest of the β-diketones and supports the phenomenon we call keto-enol tautomerism (see the illustration). Notice that the third carbon atom in the 5-carbon keto chain loans one of its hydrogen atoms in forming the enol tautomer. The freedom to move of this hydrogen atom suggests acetylacetone is a weak acid.1 In effect, the saturated di-ketone becomes an unsaturated di-alcohol. Only instead of two hydrogen atoms, one to each oxygen atom, there is just the one hydrogen atom that must be shared. Preparation Commercially, acetylacetone or H(acac) can be prepared from isopropenyl acetate by heating it in the presence of an appropriate metal catalyst. Dissociation and Reaction Since it is an acid, it can ionize or "disassociate", giving a positive…

06Jun 2018 by Vincent Summers No Comments

Our Planet and Atmosphere: Ozone – the “Other” Oxygen

Health, Technology

[caption id="attachment_20184" align="alignright" width="440"] The Blue Ridge Mountains of Virginia[/caption] Oxygen atoms are very reactive chemically. We call them electrophilic or "electron loving" because the oxygen atom seeks to bind to other electron-rich sources, especially itself. Thus oxygen is present in our atmosphere primarily as the molecular O₂. Another Form A small percentage of atmospheric oxygen exists in another form, ozone, O₃. This less stable form of oxygen is produced by ultraviolet light or high voltage electrical discharge. It's garlicky odor may be discerned after a heavy thunderstorm. Geometry The O₂ molecule consists of only two atoms, and two points make a line, right? So what shape is the O₃ molecule? Unlike its more abundant companion, ozone is non-linear. As a result, it carries partial charges on its constituent atoms.…

15Mar 2018 by Vincent Summers 5 Comments

Initiating a Fission Chain Reaction: What is Critical Mass?

Physics, Technology

[caption id="attachment_19651" align="alignright" width="600"] One basic fission reaction[/caption] What is critical mass? Before we answer that question, we want to discuss the topic of fission, itself. When we speak of atomic bombs, we do not usually mean hydrogen bombs or fusion bombs in which the nuclei of hydrogen atoms fuse together.¹ Rather, we mean fission bombs, in which large atoms of radioactive (unstable) elements are torn apart to produce smaller atoms with the release tremendous energy. One simple atomic explosion reaction is written, 1 n + 235U → [236U] → 92Kr + 141Ba + 3 n The above equation informs us that one energetic neutron properly striking an atom of uranium, isotope 235, produces, first and temporarily, an ordinarily stable atom of uranium, isotope 236. [caption id="attachment_19652" align="alignleft" width="300"] Uraninite…