Year: 2013

Learning the Periodic Table: A Prototype

My middle school class is about to cover some very basic chemistry so I’ve asked them to memorize the first 20 elements in their correct order on the periodic table. To help, I’ve put together this interactive exercise where they drag an icon of the element to its correct place on the table. It says the name of the element whenever you start dragging a tile with the symbol. It’s also timed so students can quantify and compare how good they are.

Prototype exercise for learning the first 20 elements of the periodic table.

In this first prototype the elements are presented in order, but I figure that additional levels could have:

  • The elements come up at random (done).
  • Have the elements come up by vertical column (group) (done).
  • Instead of tiles with the elements, have diagrams with their electron configuration.
  • The program say the name of the element and the student has to click on the right cell in the table.

This was put together using HTML5 and Javascript. KineticJS was particularly useful. It should, in theory, work in any browser (but I have only tested it in Firefox and Google Chrome) and on touch-screen tablets as well.

Gardens Reduce Violence

A fascinating article on the relationship between environmental conditions and sociology, explains how urban community gardens — in formerly vacant lots — actually reduced violence in the areas around them.

There’s been a growing body of research that suggests that urban farming and greening not only strengthen community bonds but also reduce violence. …

Over the course of 10 years, [gradens] reduced shootings in the areas surrounding these renewed lots. Part of it was practical: The vacant lots had previously been hiding places for guns. … and … “People just became more in touch with their neighbors. People felt more connected to each other.”

— Kotlowitz and Schiffer (2012): Plant Tomatoes. Harvest Lower Crime Rates in Mother Jones.

The Science of Champagne Bubbles

This nice little video combines a bit of physics, chemistry, and biology as it discusses how bubbles form in champagne: the gas is carbon dioxide; carbon dioxide forms from the fermentation of sugars by yeast — it’s a byproduct of the reaction that produces alcohol; the bubbles form at tiny flaws or bubbles in the glass (so you can put in tiny flaws to control where the bubbles form); the bubbles rise because the gas is less dense than the liquid around it; and the bubbles expand as they rise because the pressure of the liquid becomes less and less the closer to the surface you are.

↬ The Dish

Fish Genes in Tomatoes

PBS has a nice list of genetic modifications to four different plants. First on the list is the antifreeze gene from a fish that was inserted into a tomato. The tomato was infected with a bacteria that had the gene in a genetically engineered plasmid. The PBS site also discusses Bt Corn, which produces it’s own pesticide, Golden Rice, which produces it’s own beta-carotene, and the herbicide resistant Roundup Ready Soybeans.

Golden Rice produces beta-carotene, which the body uses to produce Vitamin A. Two genes, one from daffodils and one from a soil bacteria, were inserted into the rice DNA. Image from the International Rice Research Institute (IRRI) via Wikipedia.