Magical liquid!

Most years, I give my students some freedom after the AP chemistry exam. There's still so much more chemistry to learn, but I've completed the required curriculum for the year, so we can explore a few cul de sacs of chemistry.

We've played Minecraft because they told me there was a bunch of actual chemistry involved - which turned out to be kind of true. There's certainly a whole bunch of material science involved.

I've also had them research chemistry programs as universities around the midwest, practice and perform a demonstration for my non-AP course, and honestly - write a blog post for my chemistry blog. 

Today's post, however, is about the time my students asked if they could just make slime. We make polyvinyl alcohol slime in first year chemistry, but they wanted to make glue (which I recognize is often PVA-based) slime. One of the students said she had a gallon of Elmer's school glue at home from her Covid lockdown slime days (apparently slime-making was a thing for many school-age students during Covid lockdown?)

In discussing what they could bring in, other students in the class offered to provide shaving cream (apparently to make 'cloud' slime - a fluffy variation), small fruit-shaped slime charms, glitter, and non-staining food coloring. I, generous sort that I am, offered my leftover borax solution from the crystal making experiment early in our matsci curriculum. It's a little more than the 4% concentration called for in most slime recipes, but it's close enough.

One of the students asked me if the borax solution took the place of the activator. I'd never heard of an 'activator' solution before, so I started looking around online.

Apparently the borax solution + PVA/glue solution with which I am most familiar has some alternatives - sort of. There's the 'borax-free' variety using baking soda and contact solution, but the contact solution has to contain boric acid - which would be neutralized into...um...sodium borate (aka borax) with the addition of sodium bicarbonate (baking soda). There's also the option to just purchase pre-mixed activators, one of which - shown in the image - is Elmer's Magical Liquid.

With a quick check of the Magical Liquid's SDS, I see that it's a solution of boric acid, sodium bicarbonate, sodium chloride (?), and a couple of anti-microbial agents. The various concentrations seem lower than I would have thought: <1% boric acid, 1-5% sodium bicarbonate, <1% sodium chloride, and <0.5% of each of the preservatives. I'm feeling too lazy to do the math to do actual calculations, but I'm pretty sure the combined percentages - discounting the bicarbonate and the chloride masses - would come out decently below the 4% of the borax solution I'm used. Wonder if that's just a case of commerce allowing for the lower concentration leading to more needing to be purchased.

At $17 per quart (from Amazon as of 6/7/26 when I'm typing this up), the magical liquid has to be a high margin item for Elmer's. It's more expensive if you want your slime to be green-apple-scented. Sadly the cherry limeade scent looks to be sold out and might be out of production now - even though Elmer's still has it listed on their website.

Cherry limeade's my favorite...grape's favorite, too.

One of the problems with Tower Heist

I can admit to having not seen the movie Tower Heist. I'm okay with that fact since the reviews generally weren't all that positive.

To give you the relevant summary, a bad Alan Alda has stolen money from lots of people including the employees of the building in which he lives via a ponzi scheme. The employees break into his apartment to steal back the money only to find the safe empty. Luckily, they happen to scratch the paint job on vintage Ferrari in the apartment and find that it's made of solid gold.

Bad science ensues.

In the above clip, nebbishy Matthew Broderick does some quick math and states that the car weighs 2000 lb at $1872 per ounce of gold which makes for about $45 million.

The math doesn't even check out as 200lb x 16oz/lb x $1872/oz = $59.9 million...even allowing the 'give or take ten million,' that's lazily off.

But the issue here is that a 2000lb car made of steel, rubber, and glass wouldn't translate to the same weight in gold since steel, rubber, and glass have different densities than gold.

2000 lb of gold would make for a cube roughly 14 inches on a side because gold is way more dense than steel, rubber, or glass. If the Ferrari were actually made of gold, it wouldn't be 2000 lb; it would be more like more than - according to one article I found - 10,000 lb...because gold is very dense.

Which would lead to so many problems in the subsequent scenes when the team tries to lower the Ferrari down on a rope, swing it into an apartment being renovated, and then has to pull the Ferrari back up the roof where a single person unhooks it and drops it into the rooftop pool.

Oh, spoilers...

None of that would be possible with a solid gold Ferrari weighing in excess of five tons.

Then, in the touching end scene, each of the building's employees gets a chunk of the solid gold mailed to them - a grill, a wheel, a bumper - all of which are easily delivered by a friendly UPS-type man...and each of which would weight hundreds and hundreds of pounds.

Shipping would be pricey.

Metal in Movies is WRONG

I know that you'll be shocked to hear this, but sometimes things in movies aren't real.

Go ahead, take a moment to let that sink in, to let the shock wear off.

In today's video Nate From the Internet addresses times when metals aren't dealt with appropriately in movies - primarily because of the density of heavy metals like gold and because of the black body radiation that should be given off when metals are hot.

I had noticed a couple of these myself - the 'molten' gold in The Hobbit and the weight of gold in The Italian Job 'remake' - but neither took me took much out of the movie. In the case of The Hobbit, it's because I wasn't enjoying the movie anyway. In the case of The Italian Job, it's because the cast is just so darn charismatic that I enjoyed the movie anyway.

The pastry and marble counter myth

I demonstrate something like this in my classroom using Flinn's ice melting blocks and a knock-off MiracleThaw from a second-hand store.

As one of the comments for the above video notes, "Thermodynamics is often very counter-intuitive." 

See, it's funny because Adam's talking about counter materials in the kitchen.

I'll wait while you laugh.

Remember, vinegar leg on the right.

The Periodic Table: Every Year

The discovery of the periodic law and subsequent creation and refinement of the periodic table stands beside the discovery of atoms as the be all and end all of chemistry in my eyes. 

Realizing that the material of our world corresponds to an underlying organizational principle and being able to - even if bit by bit - understand that principle is absolutely stunning to me.

Today's video looks at how what we think of as the modern periodic table came to be, from initially un-organized list of elements through to a quantum-mechanical-model-based periodic table.

Some of the changes come and go fairly quickly in the video, so be ready to pause and review the notes as the video plays.

Making of a jacketed glass chemical reactor

Source - reddit

Scientific glass blowing is just so amazing to watch.

There was an attempt...to put out an oil fire

Source - reddit

Don't use water to put out and oil/grease fire.

Ever...

See, if the oil is hot enough to catch fire, it's hot enough to boil any added water.

Boiled water means the oil being aerosolized into tiny, incredibly flammable droplets which catch fire and turn a small fire into a raging inferno incredibly quickly - as the above video shows.

Instead, smother the fire.

Put a lid on the pot.

Put a baking sheet on the pot.