Category: Useful websites

Quick Chemical Formulas

ChemEqn app.

While teaching chemistry this year, I’ve needed a quick way to write chemical formulas. The fastest thing to do is just write it out flat–sans sub and superscripts–like Na+, or CO2-. But that’s not pretty, and introduces another potential element that could confuse.

I found that you can use Lingojam’s sub and superscript generators to copy and paste the official UTF-8 characters for pretty much all the sub and superscripts I need for chemistry, but that takes a while to do.

So instead, I put together, just in time to write my finals, a little ChemEqn app that uses keyboard shortcuts to quickly substitute in the sub and superscripts as you type.

  • [Ctrl][number]: give you the number subscripted:
    • e.g. [Ctrl][2]: gives ₂
  • [Ctrl][Shift][number]: gives superscripts:
    • e.g. Ctrl][Shift][2]: gives ²
  • [Ctrl][Shift][+]: gives a positive charge (⁺)
  • [Ctrl][Shift][-]: gives a negative charge (⁻)
  • [Ctrl][>]: gives a forward arrow (→)
  • [Ctrl][<]: gives a backward arrow (←)
  • [Ctrl][/]: gives the double arrow (⇌)

The method is not perfect, since you still have to decide which comes first when you have both a sub and superscript after an element (O₃²⁻ for example). Another issue is that when I do [Ctrl][Shift][+] and [Ctrl][Shift][-] it zooms into and out of the browser window since we’re using the default zoom shortcuts, but that’s, at least for me, a minor inconvenience.

I do like the app since it still makes for quite readable formulas that can be easily copied and pasted almost anywhere without messing up since it only uses UTF-8 characters that are pretty standard across the web (and most computer programs).

Useful Games and Apps

Ellen Holderman has an excellent post about “24 Apps, Games, and Websites Teachers are Using in STEAM Classrooms” that are mostly free. (STEAM stands for Science, Technology, Engineering, Arts, and Mathematics).

They’re mostly aimed at a younger audience–middle school and below–, but there are things like Khan Academy that’s useful for all ages. Quite a number have to do with introducing coding.

↬ Ms. Lannert.

Investigating the Heart Online

BodyXQ has one of the most impressive interactive apps of the heart that I’ve yet seen.

Observing the heart with BodyXQ.
Observing the heart with BodyXQ.

You can explore the heart in 3D while it’s in motion. You can see the valves open and close, while hearing the beat. I’m going to have to show this to the class tomorrow.

Embeddable DNA

Ravenclaw’s four genes on the DNA string annotated. Note that start and stop codons bracket each gene, and there is non-coding (junk) DNA between each gene.

Using English words like “blue eyes” to represent genes in DNA strings with the DNA Writer runs the risk that students start to wonder if actual genes are coded in English.

I’d say it was a small risk, but today I did have that question from a couple of students today.

Fortunately, it was quite easy to disabuse them of the impression: they didn’t actually believe it, but they just had to know for sure.

I did like one of the questions though, “Does that mean that Spanish people have DNA written in Spanish?”

Embedding the Tiles

With that caveat, since I, and a few of my students, like the pretty patterns the DNA Writer produces (see above), I created a way to embed the color sequences into other webpages like this blog.

By default, the embedded image links back to the DNA Writer website, but you can adjust it so that it does not. Instead, the nucleobase tiles will change color when you click on them. The color changing helps keep track of where you are if you’re trying to string the sequence in beads.

For academic purposes, you can also change the message you get when the mouse hovers over the tiles. By default it give the plain English translation, but you can make it say whatever you want, or even have it just show the base sequence.

Millennium Development Goal Tracker

Tracking international commitments and progress on the Millennium Development Goals via Health Intelligence.

We covered the Millennium Development Goals in Environmental Science this past quarter. However, the big outstanding question was how close have we come to meeting any of the goals. Health Intelligence hosts an excellent, interactive map for tracking progress on the Millennium Development Goals.

Anatronica: 3d Anatomy Online

Screen captures from Anatronica's Anatomy 3D Systems website. The digestive system is highlighted, while the skeletal system is shown semi-transparently for context.

Anatronica has an excellent, online, 3d viewer for the anatomy of the human torso. While it’s not quite the same as a physical model, it’s pretty good as a study guide for middle schoolers.

Plugging Latex Equations into Webpages

I’ve figured out how to put latex equations into this WordPress website, but have been struggling trying to get it on my other math based web pages, like the parabolas page.

Now, however, I’ve discovered CodeCogs, which provides an excellent Equation Editor that allows the inclusion of latex equations on any website (html page).