Chemistry

Kudos to Thames and Kosmos for getting their chemistry sets on the shelves at Barnes and Noble. They have these three introductory sets in the store: the “Dangerous Book for Boys Classic Chemistry Science Kit,” “The Chem C500,” and “The Chem c1000.” Sadly, the chemistry set has to compete with the Xbox One and the Play Station 4 so, if there’s any money left over for after Christmas sales you’ll at least have the opportunity to browse the three sets in the store—pick up the box, feel its weight, read the back of the box for the contents and information about the experiments that can be done…

Life grew as a result of natural processes that used Earth's raw materials. Models of life's origins almost always look to minerals for such essential tasks as the synthesis of life's molecular building blocks or the supply of metabolic energy, but this assumes that the mineral species found on Earth today are much the same as they were during Earth's first 550 million years — the Hadean Eon — when life emerged. A new analysis of Hadean mineralogy published in American Journal of Science challenges that assumption. Carnegie's Robert Hazen compiled a list of every plausible mineral species…

Edward Snowden: patriot or traitor? Whatever your opinion of Mr. Snowden, he did give us pause to reflect on our Fourth Amendment rights “of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.” When contemplating the problem, one must first answer why the Fourth Amendment was considered so important that it needed to be added to…

While driving to my doctor's office to get some persistent Toxicodendron diversilobum (that's poison oak) looked at, I listened to NPR. Just as you would expect of me, my radio stations will all have buttons for NPR, country music, whatever station carries Rush Limbaugh, and a variety of others. On NPR I was intrigued because the guest chef was preparing a meal for alternative Thanksgiving lifestyles, that being vegan and gluten-free. Now, people may object to persistent claims that going gluten-free is a fad rather than a health issue for the overwhelming majority of people now embracing…

Some older chemistry sets included a conductivity tester to demonstrate the conductivity of materials and liquids. If you wish to include Snap Circuits in your Science Play and Research Kit you can use a simple circuit designed with the 555 timer IC incorporated into the circuit to test conductivity. For an introduction to the 555 timer IC and snap circuits, please review this article. Parts Needed: 1 555 Timer IC 2 Clothespins 1 250 ml beaker Snap Circuits Parts: 1 Base Grid (11” x 7.7”) # 6SC BG 1 Eight-Pin IC Socket # 6SC ?U8 0.02uF Capacitor # 6SC C1 1 Variable Resistor #6SC…

You may wish to include a UV LED in your Science Play and Research Kit. Nowadays you can find inexpensive key chain lights that include a visible light LED flashlight, but also include a red laser LED and UV LED. The red laser can be used to demonstrate the Tyndall effect, and the UV LED can be used to demonstrate  a lot of stuff that becomes visible under UV light. I found this black light (UV) LED strobe light on clearance after Halloween for around $2.00 USD: Here’s a better picture: (Source) The beaker filled with cloudy liquid is actually a few drops of milk in water…

You may wish to include a UV LED in your Science Play and Research Kit. Nowadays you can find inexpensive key chain lights that include a visible light LED flashlight, but also include a red laser LED and UV LED. The red laser can be used to demonstrate the Tyndall effect, and the UV LED can be used to demonstrate  a lot of stuff that becomes visible under UV light. I found this black light (UV) LED strobe light on clearance after Halloween for around $2.00 USD: Here’s a better picture: (Source) The beaker filled with cloudy liquid is actually a few drops of milk in water that I…

You can use a laser to demonstrate the Tyndall effect. A simple cat toy (laser pointer) will do but for this demonstration I’ll be using the laser from my DIY Laser Interferometer. “The Tyndall effect, also known as Tyndall scattering,” according to Wikipedia, “is light scattering by particles in a colloid or particles in a fine suspension.” You can use the laser to test three different mixtures: solutions, colloids, and suspensions. Parts needed: 250 ml beaker Teaspoon Eyedropper Table salt (NaCl) Milk Dirt from your garden Tap water Solutions Stir 5 grams (1 teaspoon) of table salt (NaCl)…

You often see demonstrations of titration using an expensive glass burette, but you can build titration lab ware using a disposable serological pipette, a solder sucker bulb, and a ring stand or support stand. For this build I’m using my erector set support stand (I sometimes call it my Bunsen burner stand). Titration is the process of determining the unknown concentration of a solution by adding a known amount of a solution with a known concentration. For example, in an acid-base titration, you can determine the unknown concentration of an acid in a solution by adding a base solution of…

Tiny self-assembling transport networks, powered by nano-scale motors and controlled by DNA, have been developed. And the system can construct its own network of tracks spanning tens of micrometers in length, transport cargo across the network and even dismantle the tracks. Researchers were inspired by the melanophore, used by fish cells to control their color. Tracks in the network all come from a central point, like the spokes of a bicycle wheel. Motor proteins transport pigment around the network, either concentrating it in the center or spreading it throughout the network. Concentrating…