September 29, 2025

Why Lithium Is Dangerous But PERFECT For Batteries

Our chemistry book has a diagram of a battery in the electrochemistry chapter, and I discuss that battery for a bit before explaining to my students that the basics of ACME (anode, cathode, metallic path, electrolyte) hold for every battery but that the engineering of modern lithium-ion batteries is far different from the diagram in the book.

This video - again leaning into the algorithm-rewarded longer and longer format - explains some battery basics involving the activity series, the history of the development of the lithium-ion battery, and the methods of fiery failure when the battery overheats.

This is, as Dr Derek says, a technology that has allowed our modern, battery-dependent world.

September 22, 2025

H and Cl sitting in a tree

On Valentine's Day (2/14/25) this year, Google's search engine graphic (the one in the top left of the page) was this cute, little bit about hydrogen and chlorine being in love.

I pretty consistently tell my students not to personify atoms and molecules. They don't have hopes and dreams. They don't fall in love. They simply move to more stable arrangements.

...but...

It's very cute to think of H and Cl being in love and holding hands, so I'm going to let Google slide on the cuteness factor alone.

September 15, 2025

Units matter


Source - Reddit
There is a significant problem with this question.

It's similar to one that Steve Mould brought up in a video I previously posted on the blog.

To say that the temperature is tripled is incredibly vague. As I teach in the unit of gas laws, to discuss temperature tripling (or doubling or whatever) we have to consider things in their absolute temperature. 

Doubling a temperature in Celsius or Fahrenheit would just double the portion above an arbitrary zero (freezing water for Celsius or the freezing point of a water/ice/ammonium chloride solution for Fahrenheit). That wouldn't really double the thermal energy or the average kinetic energy of the object because there's a whole bunch of that below the arbitrary zero.

To actually double the thermal energy or average kinetic energy, you would have to double the absolute temperature, something measured in either Kelvin or Rankine scales.

So it looks like Duolingo doesn't understand that aspect of temperature.

September 8, 2025

Where is he? We'll never know.

 

Source - Brewster Rockit

See, it's funny because it's a reference to the Heisenberg Uncertainty Principle in which - in a very simplified format - we can know the momentum or position of a particle but never both. 

I warn you, the uncertainty principle is a whole lot more complicated in its real form, but unless you're really into quantum mechanics, I recommend that you take the simple version instead.

With larger objects - say a person or a baseball - we can know the two quantities about the object almost perfectly, but as the object gets smaller - like atoms and protons and electrons or a shrunken Brewster Rockit - we can know less and less about the combination of the two quantities.

I get it. It takes some subtlety and understanding of the world of quantum mechanics to get the joke.

Luckily, I get the joke...like I got this other, similar one.

September 1, 2025

That's hydride.

Source - SMBC

See, it's funny because...well, honestly I don't necessarily understand why it's funny in a scientific sense.

I get that - as is often the case in many genie stories - the genie fulfills the wish as spoken but not necessarily as the person intended it to be fulfilled. It's a fairly common trope, donchaknow.

But there are hydrogen atoms with two electrons or at least hydrogen ions that have two electrons. I guess changing every hydrogen atom to hydride ions (hydrogen with two electrons) would cause some problems, but I don't necessarily know that all of that would lead to immediate explosions. 

August 25, 2025

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.

August 18, 2025

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.