Phase Change Materials. wmv

I remember the Cincinnati Bengal mascot coming to our school a decade or so ago, back when Becky and I were running the Pasta for Pennies campaign (and raising $30K-40K in a month doncha know). He was there for what we called the Wacky Olympics, a celebratory picnic and bunch of games that we held at the end of our fundraising year. We would have grade-level (and staff) teams compete in stupid games (pass the orange, four-legged race, stuff like that), eat hot dogs, drink punch, and generally have a blast.

One year the local Leukemia and Lymphoma Society chapter arranged for the Bengal mascot to come out and celebrate with our students. It happened to be a nice, 85-degree day, though, so I was a little worried that our mascot would end up with heatstroke. He explained to me that he had 'ice packs' that weren't really ice under his costume. Those packs were filled with a material that undergoes a phase change from solid to liquid at around 70^oF, meaning that they'll have a stable temperature at that range for a long time, keeping the mascot-suit-wearing human close to that temperature for a long time.

The video up top shows a material similar to that being used in wall materials to keep the office at a fairly stable 23^oC (73.4^oF).

The videos below show something a little more like what the mascot wore under his costume.







How cool is that?

Colourful Chemistry: Chemistry of UNIVERSAL INDICATOR

Source - James Kennedy

Back in the day, we didn't get a whole lot of science educational content on television. It was pretty much just Mr Wizard, and by the time I was watching him, he was in reruns on Nickelodeon.



If you haven't seen Mr Wizard, you should check it out before watching Sam Rockwell's science skit on Saturday Night Live.



There certainly are days when that feels all too familiar. Thankfully, I don't drop the language that Sam Rockwell did.

But I digress...

In that first video up there, Mr Wizard explains to his young assistant how you can check the pH of a solution using an indicator solution of red cabbage juice. I've done the red cabbage experiment, and it's a blast. The cabbage contains anthocyanins that change color depending on the pH.

In the chemistry lab, though, we rarely use red cabbage juice. Yes, some science suppliers will sell it, but most would much rather sell a solution of universal indicator, made up of a solution of four indicators that produce a lovely and in-order rainbow of colors as the pH increases.

Thanks, by the way, to James Kennedy for putting the top-most infographic together.

Super Expensive Metals - Periodic Table of Videos

Are they really worried that The Professor is going to rob the place that they had to strip him and even take away his belt?

Rhodium, iridium, palladium, and platinum are impressively un-reactive, noble metals.

In the video today we get to see these catalytically useful metals being processed from sponge (what I would think of as ore).

I love seeing what I think of as a crude process like forging being used to reshape the incredibly expensive ingots.

And I doubt these are the absolutely most expensive metals out there - I'd put the sodium from previous videos up there - but it is a chance to answer a question I get from students from time to time: "what is the most expensive element?"

Corrosion in Motion Golden Gate Bridge

I just love the special effects from the first half minute of the video. The tentacles, in particular, are hilarious.

The explanation (1:25) of a single piece of iron having both anodes and cathodes due to random electron movement, however, is actually really good. I wish they'd go into more depth there.

Don't Play With ACID SLIME

Why would you ever think that making acid slime was a smart thing?

Making a video and project based on a moronic YouTube comment seems like a really bad idea, not necessarily anything especially dangerous, just something dumb.

The acid clearly doesn't let the slime 'set up' which isn't really all that surprising because polyvinyl alcohol slime holds together via cross linking (check the graphics here), and the extra hydrogen ions would likely break down all of those cross links - if not even depolymerize the PVA.

The pH test strips, by the way, are absolutely useless there because all of the acids that they're testing would have pHs well below 1, leaving them likely outside the useful range of the strips.

That was dumb.

Crystal Birth

Crystal Birth from Emanuele Fornasier on Vimeo.

That's just pretty...and relaxing to watch.

Here we get a bunch of chemical reactions producing metal atoms from metal ions. Some are single replacement reactions. Some are - I think - electrical reduction (I'm assuming that because there are gas bubbles appearing in some of the reactions).

For the most part, we get very little information as to what reactions are taking place, with the only text in the video saying things like Bi⁺³ --> Bi but not mentioning any anions being involved.

Either way, this is definitely reduction happening as every reaction changes a metallic ion into the metallic atom that then forms the crystal.

Stick around for the lead crystals at the end (from about 2:23 onward). They're gorgeous.

And not lead crystal...lead crystals.

Flying squirrels secretly glow pink, thanks to fluorescence

I remember visiting the Grand Canyon a few years back and getting a post-sunset tour from the park ranger. He took a ultraviolet flashlight and looked around at the desert around us. It took him maybe ten seconds to find a scorpion fluorescing in the blacklight.



I spent the rest of the hiking trip sleeping on the picnic tables.

I haven't been shown the fluorescent, flying squirrels, but I'm thinking I wouldn't be nearly as scared of them as I was of the scorpions.

Read more about this at NatGeo or Smithsonian.

Meet Dawn Shaughnessy - the real-life alchemist who expanded the periodic table

Dawn Shaughnessy - source llnl.gov

"The periodic table is chemistry's holy text."

I love that quote, the first line in an article from gizmodo.

The periodic table - I guess the discovery of the periodic law and subsequent creation of the periodic table - is the absolute ne plus ultra (yeah, I have a big lexicon, deal with it) of chemistry discoveries. That pattern - repeating properties of the elements when lined up by atomic number - has made the world, the elements that make up our everything utterly understandable and systematic rather than a random series of unconnected substances as they seemed to be before Mendeleev came along.

But Mendeleev's periodic table only included somewhere around 63 elements (his first had 63, his last versions had more than that).

Until William Ramsay came along and added the noble gasses, discovering four elements.

And Albert Ghiorso came along and - with the other scientists like Glenn Seaborg in his various labs - added in a dozen man-made elements.

The newest additions to the periodic table aren't necessarily the work of solo chemists toiling away in laboratories. They're the work of collaborative efforts between scientists at Lawrence Livermore National Labs (near San Francisco, CA), the Joint Institute for Nuclear Research (in Dubna, Russia), and a few other specialized sites around the world.

One of the lead scientists, Dawn Shaughnessy, is the subject of the gizmodo article linked above (and here again). She and her team have been instrumental in discovering six elements, the last four of which only received names just three years ago. Plus her team donated a $5000 grant to Livermore High School's science department, which is pretty cool.

Oh, if you wanted to know how new elements are created, check out this video...



...or this one about the search for elements 119 and 120...

Rare World Metals Mint

Check out Rare World Metals Mint.

They sell - and I know this will shock you - rare metals that have been minted.

Mostly they sell one troy ounce samples of rare metals in high (99%+) purity. They don't do bulk. They don't do raw. They just sell these samples for - as far as I can tell - collectors who want to have rare metal samples.

They do offer some relatively inexpensive offerings.

• a minted AVDP ounce of copper, for example, is going for $1.49 as I type this
• nickel is $3.95 per AVDP ounce
• zinc for $8.95 per troy ounce

but things go up quickly from there...

• rhenium $179 per troy ounce
• iridium $1895 per troy ounce
• palladium $58.95 per gram
• osmium $965 per troy ounce
• rhodium $3500 per troy ounce
• platinum $59.50 per 1/25 of a troy ounce

...because why not splurge if you're going to collect the good stuff?

As they write at the end of their rhodium description, "own what's rare!"

I wonder if they have a wishlist feature so I can make life easy for my loved ones this Christmas...

How big is a mole? (Not the animal, the other one.) Daniel Dulek

Gotta love the TED talk animations.

We use the term mole in chemistry when we're calculating how many atoms (or molecules or formula units) are in something, or how much of a substance is needed to react with another substance.

A mole is 6.022 x 10²³ of something, but that's a ridiculously large number to try to conceive of.

It's 602 200 000 000 000 000 000 000. It's HUGE, but that's okay because atoms are tiny, like really tiny.

2019 Nobel - lithium-ion batteries

Source: XKCD

That's not really what the 2019 Nobel prize in chemistry went to, but it would be funny if it had.

Instead, the 2019 Nobel prize went to a trio of scientists who developed the technology for lithium-ion batteries.

Plutonium

Source - https://xkcd.com/2115/

Rollover Text - It's like someone briefly joined the team running the universe, introduced their idea for a cool mechanic, then left, and now everyone is stuck pretending that this wildly unstable dynamic makes sense.

See, it's funny because the concept of a solid chunk of metal just generating energy for billions of years is just ridiculous.

Except that it isn't.

Nitromethane Jet Bottle - Looks Awesome in 4k Slow Motion - aka Whoosh Bottle

The whoosh bottle is among my favorite demonstrations.

It's easy as pie to set up. It allows some phenomenal chemistry to be shown (limiting reactants, combustion, exothermic reactions, energy transfer).

And it looks gorgeous.

I'm not sure that the nitromethane woosh bottle adds anything cool, but the slow-mo, 4K video definitely does.

$500,000 of Calcium - Periodic Table of Videos

I think it's necessary to watch the below video first to understand the above video.

Take a couple of minutes. I'll wait.



It's the moment at 2:50 where they mention at the "cost of the calcium they consume is 10% of the operation costs of the machine" that got me.

That and the fact that Yuri Oganessian is there...talking. He's only the second person to have had an element named after himself while he was alive and the only person currently alive to have that happen.

He is among the greatest chemistry (or physicists) alive.

Back to the calcium, though. I initially wondered about why the calcium would be so amazingly expensive, thinking maybe it had to do with simple purification to make sure there weren't any non-calcium contaminants. But I hadn't thought about the need to only use heavy isotopes of calcium - specifically calcium-48 - for the nuclear synthesis. Purifying calcium's mixture of calcium isotopes into just calcium-48 (0.187% of all calcium atoms according to wikipedia and confirmed by webelements) is apparently tough...and expensive.

I especially appreciate that the Professor mentions (at 1:40 in the top video) that his shaky hands prevent him from even touching the vial of calcium-48 carbonate.

Where Do Trees Get Their Mass?

Last week we saw a video that asked us what happens to the mass you lose when you lose weight.

This week we look at the reverse. Where does the mass come from when a tree grows?

It's a remarkably similar answer because generally, reactions are reversible.

This question is incredibly subtle, and not even high-level science students get it right...



As a side note, I can see through Dr Derek at about 3:50.

The mathematics of weight loss | Ruben Meerman | TEDxQUT (edited version)

Mrs Heckman and I were having a discussion one time about what happens to the fat - or whatever else - you burn when you lose weight. My contention at the time was that the fat was turned into carbon dioxide and water vapor which was eventually exhaled from your body - mostly as carbon dioxide but less as water vapor.

I don't, honestly, remember what her contention was...because it was wrong.

I do love the explanation of what the arrow (at about 5:00) actually means.

In the long run, it's just conservation of mass, and when we're talking about 'invisible' gases, it's an incredibly slippery concept for being so simple.

In all honesty, if my students could successfully answer the question he asked of the sunbathers on Bondi Beach, I'd be pretty happy about their conceptual understanding of chemistry.

There's a flip side to all this, and I'll post about that next week.

How Not to Put Out a Metal Fire - with Steve Mould

I remember watching WGN a couple of decades ago about a fire at a metals recycling company in Chicago (maybe this one?) The thing that fascinated me at the time was watching the firefighters spray water on the fire, have it explode, and repeat the process a couple more times. The fire chief at the time - in my deep memory, at least - said something to the effect that they knew the explosion was likely but that they were trying to dump enough water on all at once to cool the fire enough to stop the burn. Not enough water = explosion, though.

In the above video - the Royal Institute - Steve Mould shows why magnesium fires are such a bear to put out. They don't - as the article linked above says - 'produce their own oxygen', but they do tear oxygen off of carbon dioxide and water. Once that happens, then, the fire allows the hydrogen and oxygen (from water - or oxygen and carbon (from carbon dioxide) to react with the magnesium or with each other producing an even hotter flame.

Hmmm...seems magnesium's active or something.

(And I don't think - at 2:55 - you 'can actually see [the beaker filling with carbon dioxide]', Steve. My understanding is that carbon dioxide is invisible. What I think you're seeing is fog, condensing water vapor due to the coldness of the dry ice.)

Bagged Water in Space Has Weird Bubbling Behavior

I'll admit to being a sucker for just about any 'in space' video.

Here we see - and the space.com article explains - air bubbles not separating from the water surrounding them in a plastic bag 'in space'.

It looks impossible but makes absolute sense because it's not the IMFs that separate water from air on Earth's surface but rather the pull of gravity. Gravity pulls more strongly on the more dense water, so the water goes down and pulls together to 'push' the air upward.

No gravity, no pull...no buoyancy...no separation.

How cool is that?

WashU Expert: The global helium shortage hits home

Source - https://www.thoughtco.com/why-do-helium-balloons-deflate-4101553

It's been a decade or more since I first started hearing about a pending helium shortage.

But I didn't notice anything since then.

Sure, Party City posted something about the helium shortage, but I can't remember that last time I bought a helium balloon. I don't care about Party City being able to fill balloon orders or not.

We don't, admittedly have the most reliable helium 'production' system.

Three main sources produce some 75 percent of the world’s helium — sites in Qatar, Wyoming and Texas — > according to gas industry publication Gasworld. In fact the U.S. has for decades provided much of the world’s supply (from cnbc.com)

...and...

A versatile gas, helium is primarily used in electronics and semiconductor manufacturing and is particularly important for medical imaging, such as magnetic resonance imaging (MRI).

Helium is used as a cooling agent in MRIs and in manufacturing processes. Because helium is stable and does not react with other elements, it is also used in the making of semiconductors to create a contamination-free environment.

Still, the biggest consumer use of the gas is in party supplies — and that area is being hit especially hard by the shortage. (again, cnbc.com)

...

[A]nywhere between 50 and 200 of Party City’s 850 stores don’t have any helium in their tanks at any given time. (again, cnbc.com)

As I write this, Party City has announced the closing of 45 stores nationwide, including the one nearest Princeton High School, but we're going to be out a lot more than party balloons in the scientific realm unless we can either produce more helium (an unlikely outcome based on what I know about noble gases) or use it more efficiently.

Source - https://boingboing.net/2019/05/10/helium-shortage-deflating-part.html

As with so many things, I blame Cleveland.

World's Lightest Sold!

I've written about aerogel before (and perpetually mention the demise of my one piece).

But I haven't shown a video that uses a FLIR camera (1:00) to show the heat zones as they insulate a chocolate bunny from a bunsen burner using aerogel, where they show the industrial process of making aerogel (5:25), or especially where you actually get to see a supercritical fluid through the window (6:25 - the absolute highlight for a teacher who used to teach phase diagrams in AP chemistry), or where you get to see a mid-process 'wet' aerogel filled with alcohol (4:50).

If you happen to follow both of my blogs, you might see this double posted because of that supercritical fluid bit.

---

The above the line stuff is what I wrote over on my material science blog because those folks care more about material science. Here, though, we care more about the chemistry, so I'm going to focus on the idea of a supercritical fluid.

The basic definition of a supercritical fluid is, from Wikipedia, "any substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist. It can effuse through solids like a gas, and dissolve materials like a liquid."

See, the phase of a material depends on its pressure and temperature. We all know that water can exist as a liquid (between 0^oC and 100^oC at normal atmospheric pressure). Most folks know water can exist at even higher temperatures if it's under pressure (like in a pressure cooker). Below 0^oC at normal atmospheric pressure, water turns into a solid, but if pressure is applied (like underneath the blade of a sharp ice skate) that solid turns into liquid without warming above 0^oC.

If we graph all that, we get...

Source - http://wps.prenhall.com/wps/media/objects/4678/4791085/ch10_11.htm

In reality, water has a bunch of different solid crystal structures, so we could complicate things like this...

Source - http://ergodic.ugr.es/termo/lecciones/water1.html

...where each Roman numeral corresponds to one of the different, atypical crystal structures for ice. There isn't any real ice-nine, thankfully.

For carbon dioxide, as we see in the video up top, the phase diagram looks like this...

Source - same Wikipedia article for supercritical liquid as above

See that grey-blue area there, where it's not grey, and it's not blue but is rather a blend of them?

That's what we're seeing in the video.

And I've never seen it before.

Red Cabbage Chemistry - Sick Science! #105

...but the smell...

If you don't want to buy universal indicator, make yourself some red cabbage solution. It's cheaper. It's available at your local grocery store.

And it smells like cabbage.

You can - if you're a school - also buy cabbage extract powder from some science suppliers.

It's a great way to pass an afternoon...or just to entertain yourself while your significant other makes red cabbage to go along with the smoked sausages if you - like I - don't eat cabbage.

Results after the jump...in case you're too lazy to do the experiment yourself...

Revealing Van Gogh's True Colors

Current version (left) and digitally recolored version (right) from the SciFri story.

I have to confess that I hate Science Friday.

I like the idea of a weekly hour of science content on NPR, but I can't stand Ira Flatow. He's obnoxiously curious, interrupts his guests with inane questions, and just generally annoys the crap out of me. I prefer the show when he has a substitute host.

That being said, sometimes the guests have fascinating things to say. On this episode, Ira interviews the senior conservation scientist at the Art Institute of Chicago.

It's fascinating that the painting has faded with exposure to oxygen and light exposure and that Van Gogh knew this - not that he knew the chemistry but that he was aware of the fading of the paints overtime and painted in a way to allow for that.

Setting Fire to Glass - The "Nope" Chemical That is Chlorine Trifluoride

"Rocket scientist Dr. John D Clark famously said about the best way to deal with potential chlorine trifluoride rocket accidents, 'I have always recommended a good pair of running shoes.' "

Or, just don't go in the pool in the first place.

Chlorine trifluoride sound like something I absolutely, positively do not every want to come even remote contact with.

I love the concept of storing chlorine trifluoride inside a steel container that's been already fully oxidized with fluorine gas. In chemistry class, I mention the storage of fluorine gas similarly and use the analogy of asking the fat kid to hold onto - but not eat - your pan of brownies. The only way to do that safely is to already feed him brownies until he's sick to his stomach of brownies. Yeah, you've lost a whole bunch of brownies along the way, but your final pan of brownies is gonna be safe.



If the little dalliance in the middle of the video about hydrofluoric acid intrigues you, check out this post of mine from a few years back about hydrofluoric acid treatment.

Making metal crystals from Pepto-Bismol

Admittedly, at first I looked at this video with some excitement, thinking that I might be able to use the procedure to demonstrate reduction of a metal in my material science class - or in chemistry.

But the procedure is insanely problematic and long and scattershot in its success. There's no way that rookie science students could perform this with any level of success.

It is, however, frickin' cool to watch.

Plus the video is insanely high def.

How does your atomic garden grow?

Source - Messy Nessy Chic

With as scared as people are of GMOs at this point (and that's a whole other kettle of paranoia), I can't imagine that atomic gardening would go over too well.

I'll give a quick summary and point you to a few articles to read more, but the long and short of it is that atomic power was hip and neat and cool in the post-WWII era. Without that trend, it looks like we wouldn't have a decent swath of produce that we enjoy today - like ruby red grapefruits, for example, which are about 3/4 of all grapefruit grown in the US.

The basics are the gardens were planted in concentric circles around a radioactive source (cobalt-60 in the diagram below). The circles were to control how much radiation each ring of the crops got. Apparently the crops in the rings nearest the source would often die, but at some distance, the crops would survive but mutate in interesting ways leading to sometimes radically different crop properties.

Source - 99 percent invisible

The crops that looked promising, then, would be taken away and bred to produce more, viable offspring with the desired properties.

Yup, the radiation was used to induce random mutations...because we wanted to mutations.

Suck on that, GMO-scaredy cats...

To read more, check out...

• 99percentinvisible - a podcast and article about atomic gardening
• Messy Nessy Chic - an article about atomic gardening
• Ripley's - an article about atomic gardening
• Wikipedia - of course

Accident at Jefferson High

I'd never seen the Accident at Jefferson High video. Flinn Scientific had been selling it for years, and I'd always heard good things about it.

Nowadays, though, it looks really dated.

What follows is my running diary while watching the video for the first time...

(Edit: As of 1/1/24 I reposted a different version of the video as the original disappeared from YouTube. Add about ten seconds to all of the times below to find the same scenes in the updated video.)

1:56 - Weirdly, I would think that the various chemicals should be handled with goggles more than gloves. And saying, "one drop [of nitric acid] could burn a hole through your skin" might be a bit of exaggeration.

2:40 - I wonder how big Jefferson High is, because they have a ton of chemicals.

3:10 - A student has purple smoke pouring from a test tube. I'm curious what it was because I assume they wouldn't use anything actually hazardous to film the video.

3:20 - A student drinks out of a beaker. Remind me sometime to tell you about a student a couple of years behind me in high school chemistry. He drank out of a beaker once...once...

5:30 - Who the heck fills a balloon with acetone and lights it? They seem to let the fire burn a lot longer than seems prudent with styrofoam heads in the fume hood.

6:15 - 'Acids and bases covered..." get it?

7:40 - You know that old phrase, "be alert and proceed with caution," right? Yeah, I hear people say that phrase all the time.

8:00 - We have a spill kit (a smaller version of this) in the room, but I've never thought about putting sodium carbonate solution - or vinegar - at every lab station.

9:50 - What high school lab rooms have compressed air outlets? That's luxurious. Next I'm expecting to hear that they have a vacuum line or a distilled water tap.

11:35 - Great sound effects, folks...props to the foley department

14:00 - Ah, the twist...it was kind of predictable that Bruno knew something all along, but I did not see the twist coming.

15:20 - There's a simple enough true/false quiz. Some of it, admittedly, isn't exactly covered in the video as it's asked in the quiz.

All in all, as hokey as this is, the video does go through a ton of safe lab procedures: properly bending glass and putting it through a rubber stopper, putting out fires, heating test tubes, diluting acids, cleaning up spills, using a fire blanket, store chemicals,

Models of the Atom

Rollover Text: J.J. Thompson won a Nobel Prize for his work in electricity in gases, but was unfairly passed over for his "An atom is plum pudding, and plum pudding is MADE of atoms! Duuuuude." theory.

See, it's funny because some of those are actual models of the atom...

• 1810 - John Dalton's first experimental atomic model
• 1904 - JJ Thomson's addition of the electron
• 1911 - Ernest Rutherford's nuclear model
• 1913 - Neils Bohr added in energy levels
• 1932 - James Chadwick clarifies the nucleus with neutrons and protons
• Today - quantum mechanical model

...and some totally aren't, but I wish they were...

• 1907 - as far as I and explainxkcd.com can tell, this one's totally made up 
• 1928 - nunchuck model - how awesome would that be?
• 2008 - fivethirtyeight.com is a website that looks at the world through a statistical lens, most famously at the US national elections 

Where does the periodic table end?

The totally honest truth is that the periodic table doesn't actually end.

I mean it stops for now, but it isn't finally finished because we keep making elements. The naturally-occurring elements stopped around 92 with uranium (having skipped technetium and promethium on that journey to uranium). Since then, we've only found the rest of the 118 (for now) elements via particle accelerator, bombarding naturally occurring elements with other naturally occurring elements.

Sam Kean - author of The Disappearing Spoon, a great chemistry book - goes through some of the details of the man-made elements here in sort of answering the question about 'where does the periodic table end?'

Though as Eric Scerri wrote a few years back...

It is simply not yet clear whether the principle that elements in the same column in the periodic table behave similarly remains valid for very heavy atoms. The question is of no great practical consequence, at least for the foreseeable future. The loss of predictive power in the superheavy realm will not affect the usefulness of the rest of the table. And the typical chemist will never get to play with any of the elements of highest atomic numbers: these elements' nuclei are all very unstable, which means that they decay into lighter elements instants after being created. 

Still, the question of special relativity's effect strikes at the very heart of chemistry as a discipline. If the periodic law does lose its power, then chemistry will be in a sense more reliant on physics, whereas a periodic law that holds up would mean the field maintains a certain level of independence. In the meantime, perhaps, Mendeleev's ghost should just kick back and marvel at the success of his favorite brainchild.

1,200 Students Kept at School Overnight After Mercury Found

Mercury looks so frickin' cool. It's a metal, but it's a liquid. It's way more dense than water is (meaning it'd be tough to flush if you were stupid enough to try.)

But mercury's kind of...sort of...a little bit dangerous. Play with it too long, and you'll go mad as a hatter. You especially don't want to sit on a vat of it.

And we probably shouldn't expose kids to it in schools, even kids in Vegas.

I remember when we had mercury thermometers in schools. It wasn't all that long ago, maybe fifteen years. We've been using all digital thermometers for all those years since, but before that happened, I had a group of students - my first AP chemistry class at Princeton, 2001-2002, I think - break a mercury thermometer. They cleaned it up, put the mercury and the broken thermometer inside two Styrofoam cups taped together then into the trash, and went on about their business. They told me the next day, and I just sort of didn't tell anybody. Not much I could've done at that point, I thought, though I certainly should have told somebody above me and seen the hazmat team come in to decontaminate my room. Instead, I bought a mercury spill kit - that I never ended up using in my remaining decade in that building - and went on with my life.

If you ever spill any mercury, clean it up properly.

The truth about oxygen masks on planes

"You know why they put oxygen masks on planes?"

"No, Tyler, I don't."

Seriously, though, the oxygen mask on an airplane could absolutely, positively, 100% save your life. And it's important to understand that you should put your mask on before helping anybody else. Ask Destin if you need proof.



But once you realize that oxygen is important in case of cabin depressurization, you might wonder how the heck they carry that much oxygen. Tanks, right?

Nope, chemical reactions...initially one between lead styphnate and tetracene which is used to ignite a sodium chlorate, barium peroxide, and potassium chlorate mixture...(wikipedia, doncha know)

Neil deGrasse Tyson - The Most Astounding Fact

I've posted about Neil deGrasse Tyson's most astounding fact before, but it's probably my most favorite video ever...and it's relevant to today's video...so I'm posting it again.



A while back I posted a graphic showing where each element came from in our universe.

Today I'm posting an updated graphic because we keep learning new stuff about the universe and the element contained therein.

It turns out that scientists observed (original publication & popular translation) a couple of neutron stars collide this past year (or rather they collided like 130 million years ago, but we just got to observe it this past year.)


So, now that graphic...

Source - https://fermi.gsfc.nasa.gov/fermi10/fridays/08172018.html

The Truth about Hydrogen

The narrator is Irish, right?

I think that's an Irish accent.

The ideas around replacing combustion engines are phenomenally complex because every good idea isn't quite as good as it at first seems to be. Yes, hydrogen sounds awesome, but it's not quite as awesome as it might be because there is no free lunch.

In the end everything we do changes our world.

The above video goes through the math of the two major ways that electric cars can be powered: fuel cells (powered via compressed hydrogen) or batteries (powered via plug-in electricity at home or on the road).

12 Texas preschoolers hurt in blast from color-changing fire experiment gone wrong

Source: KHOU.com

Stop. Using. Methanol.

From The Washington Post...

The teacher mixed boric acid with methanol, Foster said, and tried to light it on fire. Nothing happened, so the teacher added more alcohol and lit the mixture again. Then there was an explosion.

It's so frickin' simple, just stop using methanol.

Even the ACS knows it.

One Town, Four Elements: Ytterby

According to the Ohio educators' Code of Conduct (7b), I'm not allowed to accept any gift from a vendors exceeding $25. That means I'm going to have to get creative in finding a way to get somebody to pay for my field trip to Ytterby, Sweden.

How frickin' cool is that? A single village in Sweden that has four elements named for it?!?!

Radioactive Boy Scout - How Teen David Hahn Built a Nuclear Reactor

In case this needs to be said, don't build a nuclear reactor in your backyard.

Even in the shed.

That's dumb.

There's a semi-well-known book about this story, but I've never read it.

I'm glad this guy wasn't anywhere near where I lived.

GIANT Liquid Nitrogen Rockets: Explodes In My Face

The title's a bit of an oversell.

Yeah, I know, you're shocked that a youtube video would use a clickbait title.

The bottle does, however, explode just above the host's head. That happens for a couple of reasons, primarily that the bottle he used for that part of the experiment is made for holding change not for holding pressurized gases and liquids. The polymer involved is more rigid, weaker, and assembled in two parts rather than as a single shell.

All that being said, I'm really happy with the safety precautions that the host takes. He's wearing gloves to protect against the cold and a face shield to protect his face and eyes. I do wish he had some earplugs in because the explosion can be loud, but he did at least take decent precautions.

Don't do this, folks...but do watch this.

25 Chemistry Experiments in 15 Minutes | Andrew Szydlo | TEDxNewcastle

Dude, you didn't put your goggles on for like a minute or two into your demonstrations.

That's going to be 10 points from Ravenpuff....or Huffleclaw...or Slytherdoor...whichever...

In all honesty, however, I'm kind of impressed with this guy's constant stream of chatter through the entirety of his presentation. Even when he finds himself pressed for time, he doesn't let the patter slow even a little bit.

He does seem a bit frazzled, though, but I do like all the experiments that he shows - other than the liquid nitrogen in bottles. That seems unsafe to me.

How Is Black Fire Made?

TL;DW - it involves sacrificing a virginal chemistry student to the chemistry gods...

jk

Actually, this one's pretty brilliant. It's the distinction between emission and absorption spectra.

See, when the yellow light is produced (or emitted) - as shown around 1:00 in the video - it's because electrons are bouncing up and down within the atom (as shown via a Bohr model). That's an emission spectrum.

That requires energy. In the fire that energy comes from the chemical reaction of the ethanol (remember kids, no methanol) with oxygen...burning.

When the sodium vapor light is on, however, it's providing exactly the right amount of energy to excite those electrons. Which is then absorbed by the sodium atoms in the flame, leaving behind no light at all. That's an absorption spectrum.

And that's so cool...

Why I changed my mind about nuclear power | Michael Shellenberger | TEDxBerlin

I'm shocked...

Like stunned...

I grew up in a firmly anti-nuke, Gerry Brown kinda household. My mom swears I didn't eat a grape until I was like five years old because she wasn't going to support the farmers against the migrant workers. There was always Bob Dylan playing on the record players, and nukes were nothing but death in waiting.

And nukes meant both nuclear weapons and nuclear power.

I remember visiting Marble Hill - a never-operational nuclear power plant in Southern Indiana - either during high school or college, and it freaked me out because nuclear power - which very nearly came to that power plant just an hour from my home - was a practical demon in a bottle. I'm pretty sure that my mom was one of the folks protesting against Marble Hill's construction in the early 1980s.

But it looks like my mom just might've been wrong.

The video shown above presents pretty strong evidence that nuclear power might be the better alternative to solar or wind power.

I'm going to have to do some more research.

And the video below - also from Michael Shellenberger, who appears to have a decent number of bona fides - tells the story of how nuclear power shifted from being an environmentalist's darling to being everybody's boogeyman.

Just for my students

I'll give 5 EC points to the first current student of mine to send me an email saying that they saw this message.