Category Archives: Articles

WebAssign Partners with OpenStax for Affordable Textbook Solutions

by Annie McQuaid

As a stakeholder in the education world for over 15 years, WebAssign is well aware of the heightened interest in more affordable textbooks, and we hope to become part of the solution to support low-cost options.  To support this effort,  we have partnered with OpenStax,  a company that offers free, open-source textbooks.  OpenStax is currently primarily funded through philanthropy, but plans to become self-sustaining by partnering with web-based educational companies like WebAssign to develop supplemental content that students could purchase with a support fee being paid back to the open education mission. Through this strategy, OpenStax hopes to deliver high quality education solutions that will ultimately save students an estimated $20-$30 million over the next several years.

Read the full article in Time Business to learn more about the open-source textbook revolution.

Calculating the Calendar: Leap Year

by Annie McQuaid

Today is Leap Day!  This is not only a day for exclusive sales and marriage proposal traditions, but also a chance to take a look at the science and math behind this special day.

One convenient falsehood that we are taught in early grade school is that there are exactly 365 days in a year. In fact, the earth turns roughly 365 and a quarter times on its axis by the time it has completed a full year’s orbit around the sun, which means that periodically the calendar has to catch up. A leap year contains one extra day, February 29, for a total of 366 days.  Without leap days, the calendar would be off by 24 days within 100 years.

The arithmetical formula used to calculate which years are leap years is as follows:

A leap year is any year whose date is exactly divisible by 4 except those which are divisible by 100 but not 400.

Why such complexity? Because the exact number of days in a solar year is actually ever-so-slightly less than 365.25 (it is 365.242374, to be precise), so the algorithm had to be designed such that every now and then a leap year is skipped to keep the calendar on track over the long haul.

The chance of being born on a leap day is one in 1,461. Four years is 1,460 days and adding one for the leap year you have 1,461. So, odds of 1/1,461.  Babies born on February 29th are known as “leapers” or “leaplings.”

Enjoy Leap Day this year as there won’t be another for 1,461 days!

Facts collected from BBC, NumbersGuy, and Scienceworld.

Recent Research: Chemical Education

by Annie McQuaid

Our guest blogger today is our Chemistry Visioneer, Erik Epp, who wanted to share an interesting article from the Journal of Chemical Education.

Mushroom Magic: Analysis of Metals in a Familiar Food, Joseph MacNeil, Samantha Gess, Miranda Gray, Maureen McGuirk, and Sara McMullen, Journal of Chemical Education 2012 89 (1), 114-116.

MacNeil, et al. provide a great description of lab for instrumental analysis laboratories using flame atomic absorption spectroscopy.  Though other everyday items can be used in such a lab, and they cite others, mushrooms provide an interesting case because of the sample preparation needed.

In using nitric acid to digest the mushrooms into a usable form, the students need to take into account the trace amounts of cadmium present in the acid and determine a limit of detection for this technique.  This forces the students to confront that the detection limit may not be set by the instrument used, but rather the chemicals and processes – an important point for qualitative analysis.

What neat labs do you use to get students thinking about the chemistry involved?

Cooking with Chemistry, Part 1

by Annie McQuaid
Thanksgiving is right around the corner and I’m sure many of you are planning on cooking up some delicious meals to share with friends and family.  Because baking involves a large amount of chemistry we are bringing you the answers to some frequently asked chemically-related cooking questions over the next few days.
Question: Are Copper Bowls Really Better for Whipping Egg Whites?

Answer: Yes, the bowl you use makes a difference when you are whipping egg whites. Copper bowls produce a yellowish, creamy foam that is harder to overbeat than the foam produced using glass or stainless steel bowls. When you whisk egg whites in a copper bowl, some copper ions migrate from the bowl into the egg whites. The copper ions form a yellow complex with one of the proteins in eggs, conalbumin. The conalbumin-copper complex is more stable than the conalbumin alone, so egg whites whipped in a copper bowl are less likely to denature (unfold).

When air is whisked into egg whites, the mechanical action denatures the proteins in the whites. The denatured proteins coagulate, stiffening the foam and stabilizing the air bubbles. If the foam is overbeaten in a non-copper bowl, eventually the proteins become completely denatured and coagulate into clumps. There is no going back from the clumpy mess to nice foamy whites, so overbeaten whites are usually discarded.

If a copper bowl is used, then fewer protein molecules are free to denature and coagulate, because some are tied up in conalbumin-copper complexes. In addition to forming complexes with conalbumin, the copper may also react with sulfur-containing groups on other proteins, further stabilizing the egg proteins. Although the iron and zinc found in other metal bowls also form complexes with conalbumin, these complexes don’t make the foam more stable. When glass or steel bowls are used, cream of tartar may be added to egg whites to stabilize the whites.

 

Please note that although copper is toxic in large amounts, copper bowls are safe for whipping egg whites and cream!

(Borrowed from Chemistry.about.com)

Getting Students to Use WebAssign

by Annie McQuaid

Our greatest resource for figuring out how WebAssign can work best in your classroom is through you and your fellow teachers.  This blog post by a High School Physics teacher explains his approach to getting his students to put the effort into completing their WebAssign homework, something we love to see!

Check it out now!

Getting Students to Use WebAssign

Do you have a method that worked for getting students more involved in their homework, and consequentially their learning experience?  Let us know below!