Removing Tarnish from Silver

Usually when I turn to Compound Interest, I'm looking to find a gorgeous infographic explaining some aspect of chemistry. Today's post from them (him, really), isn't graphical in the least. Instead, it's an in-depth exploration of one of the NACE labs that we perform in our summer, teacher camps: Quicksilver.

Why does the sodium bicarbonate need to be there? Andy explains.

Why do we need the salt? Andy explains.

Where does the rotten egg smell come from? Andy explains.

Why do people still buy polishing plates for as much as $30? Even Andy can't explain that.

Compound Interest is a British blog through which Andy Brunning, a chemistry teacher with a flair for graphic design, posts outstanding chemistry-themed infographics.

The Chemical Elements of a Smartphone

I am an admitted smartphone convert. After I was dropped into Salt Lake City needing a Wal-Mart, Home Depot, Lowe's, Office Depot, a bookstore, and a laundromat in the span of a few hours - all of which I found with no problems whatsoever - I don't think I can ever go back to not having the world's knowledge at my fingertips.

Admittedly I wasn't aware of just how many rare earth metals were found in my smartphone, however. Thanks to Compound Interest, now I know.

Compound Interest is a British blog through which Andy Brunning, a chemistry teacher with a flair for graphic design, posts outstanding chemistry-themed infographics.

The Metals in UK Coins

I had no idea that the University of Kentucky had its own mint - or that it used the pound instead of the dollar. Interesting.

In all seriousness, though, the metal composition of United Kingdom coins - something that is surprisingly in flux - is a lot more varied than is the metallic composition of United States coins.

And do remember that the US mint is losing money on every penny it produces. Check out just how much money over on coinflation.com.

Compound Interest is a British blog through which Andy Brunning, a chemistry teacher with a flair for graphic design, posts outstanding chemistry-themed infographics.

The Polymorphs of Chocolate

I have to admit that I have not much experience with the various crystal structures (or, as named, here polymorphs) of chocolate. In my world there's the form of chocolate that hasn't been opened yet and the form that's in my belly. Most of my research happens on the tongue .

Here Compound Interest goes through the six different structures of chocolate and how temperature affects the stability of each one, something that can be highly relateable to some of the alloys that we cover in our summer teacher camps.

Compound Interest is a British blog through which Andy Brunning, a chemistry teacher with a flair for graphic design, posts outstanding chemistry-themed infographics.

The Chemistry of the World Cup Ball

Apparently there's some sort of football futbol tournament going on in South America this month. I assume that there's something I don't understand about the game because that ball up above doesn't look like the pigskin, oblong spheroid that I'm used to.

Wait, they're playing soccer? Oh, that's different. That makes more sense.

It's apparently a pretty involved bit of chemistry in trying to make the ball as perfect as they can, as non-water-absorbant, as perfectly round, as free from drugs and cheating and shoulder-biting as it can be.

Check out the full-sized pdf of the infographic at this link and the original post - with a lot more chemical explanation - here.

Compound Interest is a British blog through which Andy Brunning, a chemistry teacher with a flair for graphic design, posts outstanding chemistry-themed infographics.

The Myriad Uses of Stronger than Steel Kevlar

Kevlar is pretty amazing stuff, stronger and lighter than a steel strand of equivalent diameter would be...unable to stop a knife but fully capable of stopping a bullet.

Compound Interest is a British blog through which Andy Brunning, a chemistry teacher with a flair for graphic design, posts outstanding chemistry-themed infographics.

What Causes the Colour of Gemstones

Compound Interest is a British blog through which Andy Brunning, a chemistry teacher with a flair for graphic design, posts outstanding chemistry-themed infographics.

The image above shows sixteen gemstones, their chemical compositions, Mohs hardnesses, and - most interestingly to me - the source of their various colours (note the British spelling, I'm so cultured, donchaknow). In summer camp we cover the idea of crystal defects - primarily toward the mechanical properties imparted with dislocations and subtitutional/interstitial/vacancy defects. Here we get the effects of crystal defects showing up as colours in the various gemstones.

How to make something invisible

The mineral oil or vegetable oil that the presenter mentions here are a little less messy to use in the demonstration, but the index of refraction with those isn't quite as perfect a match as glycerine (or glycerol) is to the borosilicate glass.

In the summer camps we demonstrate this with three types of glass - fused silica, borosilicate, and soda-lime glass. It's only the borosilicate that disappears, so the type of glass you use certainly does matter.

Solar FREAKIN' Roadways!

This video has been making the rounds on Facebook of late, positing that much of the nation's energy problems could be solved by installing solar panels in the beds of roadways around the country, that we could install LEDs in the roadway to make the signage imminently changeable on a moment's notice. It feels obvious and has raised more than $2 million to fund the project.

...but is it really feasible?

The website Jalopnik has an article running the numbers, and their conclusion is that it's pretty well a longshot, a similar conclusion reached by the ExtremeTech website. From the ExtremeTech article...

With all that said, there’s still no denying that Solar Roadways are cool — but why not just, I don’t know, put solar panels along the side of the road? Or on the roof of your house? Or in the desert? Having built-in ice and snow melting is pretty neat, and lighting up when an animal steps on the road is cute, but neither are worth $56 trillion. Rooftop solar arrays are reaching the point where they’re actually quite cost effective in certain parts of the world — and they’re much, much cheaper than building a Solar Roadway — but adoption is still very low. As much as I’d love the US to be blanketed in green, fossil fuel-replacing electrified Solar Roadways, it just isn’t feasible. On the small scale, there could well be some companies that roll out Solar Roadway parking lots — but I think that’s about it, for the foreseeable future.

Mohs Scale of Hardness

The Mohs Scale of Hardness isn't my favorite thing in the world. I'm a chemistry guy, and sometimes earth science leaves me cold.

So I totally understand this slightly modified Mohs scale from the FAKE Science tumblr.

Fake science: common crystal shapes

 

The Fake Science tumblr is exactly what it says, FAKE science...

...but it's funny science - including this post about common crystal shapes.

Your shoes are rubbish

Your Shoes Are Rubbish from Billy Turvey on Vimeo.

I don't mean to insult anybody here, because I'm sure your shoes are just super cute.

This video, however, shows a recycling effort to turn plastic waster from a beach and shoreline into a new pair of shoes. It's a gorgeous effort and seems to work, but I doubt anything this labor-intensive would be worth doing on a large, mass-production scale - especially without knowing just how comfortable the shoes end up being...

...because they look like they have no padding or anything comfortable to them at all.

...but it's neat to see.

Iron wire demo and where to buy the supplies

Update (12/1/24): You can order the wire online from Ace Hardware now - either in 50 ft lengths or in 1540 ft lengths.

For some ridiculous reason, one of the hardest supplies for material science teachers to procure is the iron wire for our iron wire demonstration. It should be the simplest thing in the world to get because it's one of the least complicated things to make, but - for some of us - it's amazingly hard to find just the right wire. Though the TruValue near Chillicothe, MO seems to stock it in bulk, my local TruValue doesn't understand what I want with it and doesn't have it on hand.

Here's (above) a picture of the iron wire (anchor wire, stovepipe wire, black wire) that is exactly what we use in the summer camps, and here's a video of the demo as we perform it, too. That's Master Teacher Caryn Jackson there on the right. She has a nice variac (and some 15-amp fuses) to use. Some of us envy her for her awesome variac.



...and the same as narrated by Beth Eddy...