How One Company Secretly Poisoned the Planet

At some point in my material science and chemistry courses, I speak bluntly to my students that most research suggests that man-made polymers are bad for us.

Some are worse than others, but most research on the effects of polymers on humans seems to suggest that there are bad effects from most man-made polymers. Some are minorly bad, but others - like the family of PFAS - are more obviously and persistently bad.

The video above is short and has a direct message: DuPont is bad (or has acted badly).

The longer video below - from Veritasium - is far longer but is much, much more informative.

If this sounds familiar, you might've seen a semi-recent movie about this story, Dark Waters.

5 Regrettable Things People Did With Uranium

Here's the list...

• Uranium glass (not actually on the list but mentioned in the introdution)
• Dentures - The uranium added to the porcelain in the 1940s helped the 'teeth' look more natural - including absorbing ultraviolet radiation like natural teeth do.
• Toys - I recognize that chemistry sets from the mid-20th century weren't remotely safe, but the current 'chemistry sets' might have swung a bit too far the other way.
• War - Not just atomic bombs here but also depleted uranium used in tank shielding and armor-piercing rounds. I've posted about this use before.
• Medicine - I hadn't heard about this use of uranium to treat diabetes before, but it sounds like it wasn't useful and was even harmful. Might want to check that whole Hippocratic thing.
• Spas - Tom Scott had a video on these spas - which sound like really bad ideas to me.

Short version - stay away from uranium, folks.

This 200-Year-Old Lighter Ignites Without a Spark

I understand that the act of creating fire at this point in our lives is trivial. 

I have a couple of piezoelectric grill lighters and a flint-based lighter in the a drawer in my kitchen. The 'pilot lights' in my gas stove, hot water heater, and furnace are all piezoelectric. If I need fire, I can have it in about two seconds.

That hasn't always been the case, of course. From prehistoric times when fire meant warmth and digestible food, the act of fire creation was miraculous and to be protected.

So the development of a 'safe' lighter that could create fire at the whims of the lighter's owner was an important step toward taming that fire.

But I certainly wouldn't want to carry around Steve Mould's Döbereiner's lamp (yes, the same Döbreiner as the periodic triads) in my pocket.

XKCD 3094 - Mass Spec

 

Source - XKCD

See, it's funny because this is a very rudimentary version of a mass spectrometer.

The person is the aerosolized sample atom which is ionized via balloon charging, accelerated by running and jumping, deflected via the magnet, and detected by position on the target on the wall.

It's almost exactly how mass spectrometry works...only ridiculously so.

Student Submitted - Hund's Rail

Source - C&EN

Today's post was submitted by Katelynn J, one of my AP chemistry students. As a sub assignment after the AP chemistry exam, I had students submit two posts for this blog. I'll be posting them over the next few weeks.

During COVID-19, this cartoon was probably especially relatable, since everyone was trying to stay as far away from each other as possible. Of course, staying healthy and safe is much more important than adhering to the buddy system, but when going into two separate cars, you’re sure to miss your travel companion at least a little.

In this specific comic, however, the problem isn’t social distancing, it’s Hund’s Rule. On the rail, representing the shells of the QMM, electrons after first fill up all empty spaces before being able to double up, since this stabilizes the atom. The two electrons here trying to enter a car together would make the atom unstable, so it’s better they stay apart.

Katelynn added that "I learned that Hund has more than one rule! His rules are best for the ground state of an atom, and all three have to do with electrons," and she found this website helpful for further reading.

Student Submitted - The chemistry of papal smoke

Today's post was submitted by Katelynn J, one of my AP chemistry students. As a sub assignment after the AP chemistry exam, I had students submit two posts for this blog. I'll be posting them over the next few weeks.

Following the death of Pope Francis, a new pope now needs to be chosen. 16-20 days after the mourning period for Francis, elections have now begun and ended, and cardinal Robert Prevost, now Pope Leo XIV, has been chosen. During this selection period, all cardinals under the age of 80 travel to the Vatican to vote, and they are isolated from society until a decision is made. In order to keep the outside world updated, after every vote, ballots are burned and either black {indicating no decision has been made} or white {indicating a pope has been elected} smoke “billows” from the chimney of the Sistine Chapel. Interestingly, the longest conclave took 3 years, following the death of Pope Clement IV in 1268.

But fire only produces one color of smoke, normally. So how are the two colors created? Originally, white smoke was made by the burning of the ballots and the addition of dry grass for a lighter smoke color, and black smoke was made by ballots, wet straw, and rosin to darken the smoke. In modern times (after 2005), a mix of chemicals are used for each color. Chemicals listed here.

This chemical cocktail works because of the state of matter changes that occur. When a substance, like the chemicals used, is vaporized (fire does that!), the particles will recondense in the air, blocking light and only allowing some colors through, the color of smoke that we see.

Learn more about how other non-white/black colors of smoke are made at this link.

Student Submitted - Fruit browning

Today's post was submitted by Aleeyah B, one of my AP chemistry students. As a sub assignment after the AP chemistry exam, I had students submit two posts for this blog. I'll be posting them over the next few weeks.

You know when you cut a piece of fruit and it turns brown after a while, or a banana peel? This article explains how to stop this from happening. This is actually because of a chemical reaction called oxidation. Fruits contain an enzyme called polyphenol oxidase, also called PPO. When the fruit is completely intact, everything stays inside the peel. However, if the fruit is bruised or cut, oxygen in the air goes into the fruit. The enzyme I mentioned before, PPO, reacts with oxygen and turns into something called melanins. This causes the browning we see. This process is called enzymatic oxidation. So the article just explains ways to slow this oxidation reaction.

I found it interesting that fruits turning brown does not necessarily mean that it is going bad. I always viewed brown fruits as spoiled, but now I might view that differently.

Learn more about fruit browning at this link.