Gimme two more!

See, it's chucklesome because the general rule is that atoms need eight valence electrons to be stable.

An atom with six valence electrons would need two more valence electrons to be stable. 

So they'd act like a guy yelling at the Subway worker for two more cookies.

If you want to know the NSFW context of the video, check it out here.

Glass bottle explosion injures students, chemistry teacher at Southport High School

The really terrifying aspect of this story to me is that I've taught in that science lab.

It's a great lab space, huge and light and airy. It's a single lab space that all of the Southport High School science teachers share and that I've used to teach our summer ASM camps. I'm hopeful that Mark Duncan - who was a great host to us for our camp - isn't the teacher mentioned in the various stories. He was more of a physics than a chemistry teacher, but none of the articles mention the teacher by name, so I can't say for certain whether Mark was or wasn't involved.

Source - msn

The woosh bottle is a demonstration that I've done countless times throughout my career. It involves putting an amount of alcohol - typically about twenty milliliters of ethyl alcohol, though other alcohols can be used - into a large bottle. The bottle is then sealed with a hand and rolled around to allow the alcohol to evaporate. The bottle is temporarily capped - in my case with a 250 mL beaker - and a source of ignition is introduced into the bottle when the cap is removed. I've used lighters or matches held by tongs or by my fingers. Early in my career, I even let a student drop the match into the bottle.

Source - The Journal Rewired

I use plastic bottles and now put the bottle behind a safety shield because of an incident I had once where the plastic bottle fell off of the lab table onto the floor in front of students sitting too nearby for my comfort. The plastic bottle is hopefully more safe than the glass bottle from the Southport story, and the safety shield makes sure that any consequences of an explosion would stay toward the demonstrator (me) and not toward the students.

...but every demonstration deserves to be reevaluated from time to time to decide if it's a demonstration worth doing. If the safety risks outweigh the educational benefits or not.

Shadows from the Walls of Death

Source - 99% invisible

There has long been question as to whether Napoleon was killed by the arsenic in the green pigment in his wallpaper. Modern analysis of the wallpaper shows that there was arsenic in it but that it likely wasn't enough to kill Napoleon by itself. Lifelong arsenic exposure did probably hasten his death but probably wasn't the final nail in the coffin.

What might kill you though, could be flipping through one of the four remaining copies of the book Shadows from the Walls of Death, two of which can be found in the University of Michigan library's rare book collection.

A hundred copies of the book were produced, showing off arsenic-containing wallpapers and not a whole lot of text - health warnings and a few Old Testament warnings about plague, apparently. Most of the copies were destroyed, but four exist - two at U of M, one at Harvard, and one at the National Library of Medicine. The Michigan copies are apparently stored with the pages inside plastic covers.

The photo with this post isn't of Shadows from the Walls of Death but rather from a non-arsenic-containing reproduction text called Bitten by Witch Fever: Wallpaper & Arsenic in the Nineteenth-century Home (available from Amazon).

You can check out the entirety of Shadows... as a pdf download from the National Library of Medicine. The safe scanning process was apparently rather laborious and is described here. 

More about Shadows... can be found in this article, as well.

The original liquid smoke controversy (it's fine, btw)

Big fan of Adam Ragusea here. 

He does a great job balancing useful cooking information, science, and his perspective on the sometimes overreaction to and misunderstanding of that science. He's also really good at integrating the sponsor ads smoothly.

In this video, Adam goes through what's in liquid smoke, how you can make it at home, and how you can use it in food.

I'll warn you that this is a much more complex look at the side products of incomplete combustion, something we barely touch upon in our high school chemistry courses at Princeton. I do mention that it's officially complete combustion that produces just carbon dioxide and water vapor but that incomplete combustion can produce other products like carbon and carbon monoxide.

Making ULTRA-BRIGHT GLOWING GOO

Barnaby Dixon is an impressive puppeteer that I first heard about probably ten years ago. If you haven't checked out some of his work, do yourself a favor and spend a few minutes there first.

In this instructional video, Barnaby explains how he uses a thermoplastic polymer - a polymer that becomes flexible when it's heated above some temperature but is rigid below that same temperature. It's a great example of the polymer's glass transition phase change. Because polymers are mixtures, they don't necessarily have definite melting temperatures as pure substances like elements or compounds do. Instead they have ranges of temperatures during which they aren't quite solid or liquid but are flexible and moldable - think of hot glass being shapeable but not liquid.

I have some of this at school. It used to be available from Educational Innovations. That's where I bought it, but they sadly don't carry it anymore. Of course, just about anything is available at Amazon if you search for pcl moldeable plastic.

How to Make a Matchbox Rocket Launching Kit

I made paperclip-rubber band bows and arrows when I was in high school. They would launch paperclips maybe ten feet and with absolutely no consistent aim at all.

This is a few quantum leaps better than my amateur armory.

Be safe out there and launch these outside and not at people...but do make them.

World's Roundest Object!

Be careful when discussing this video with your students. This is about the world's roundest sphere...sphere. It's not a ball. It's a sphere.

Just saying.

'Cause I know I've said ball in front of my high school students, and it took me a while to get the boys' attention back.

(In a related aside, my wife is listening in as this video plays. She lost control at 6:22 when the narrator said "Newtons, Joules". To quote her: "heh, heh...Newton's jewels...heh, heh".)

This 'world's roundest object' is more about the basis of our metric (now the systemé international d'unités or SI) than it is about materials science. There are, however, some serious challenges involved in making a material that won't decompose, that won't get dirty, that won't wear away, that won't change over time.

Here they have created - according to the scientist at 7:25 - a single crystal of silicon with 'no voids or dislocations' and containing only one isotope of silicon, making the material just slightly less valuable than absolutely, perfectly, priceless.