Alfredo Mateus 🧪⌬

Conheça o xciência.org, meu blog com recursos para o ensino de ciências. Experimentos, abordagem maker, uso de TICs em sala de aula e mais.

@justfredimelda I would prefer just the title on a black background than AI crap.

Will you refuse to buy a book with an AI generated cover providing that everything else is human written? #writingcommunity

@Andrestrujado @nanocotech Do they sell this demonstration kit? I am putting together an exhibit for the International Year of Quantum Sciences here in Brazil and this experiment is on my list, if I can find a source.

A massive thank you to @nanocotech for lending us this magnificent CFQD® Quantum Dots demonstration kit for our future events celebrating #IYQ2025! The wondrous fluorescent quantum dots have a bright future and many applications. Hope they inspire the next generations!

Sent my proposal for a presentation @ChemEd2025 today! ChemEd is the best conference for chemistry teachers that I have been. Looking forward to the conference and to get to know Colorado.

@Joe_____D only saw your post now, sorry... The files are here: thingiverse.com/thing:5523467

@alfmateus So cool… been looking for a reason to use the school’s laser cutter! Can you share the file so we can print in our school?

Today is laser day. I am at our school's makerspace cutting some resources for my Chemistry classes. Lots of nice things you can do with a laser cutter/engraver.

I made some Avogadro Number scrolls. A long banner with some 3D printed parts that fit on the wood bars on each edge. The idea is to make a slow reveal of the number in class, thousands, millions, billions.... up to 602 sextillions.

The students are doing an evaluation using microscale reactions today. They have to describe what they observe and draw models of what happens. Just like @UncleBo80053383 Power point animations.

@agbrolo @chemistryatuvic Congratulations, Brolo!

Leaving soon to #Niagara_Falls for the #Herzberg award presentation. #spectroscopy #Raman #nanotechnology #analytical_chemistry #icass_2024

@MrShepherdChem @StAmbroseSci @SSERCofficial If you use music you can make really build the end of the series. You can "tune" the last one for the end of the music. William Tell Overture. Got the idea from an old JChemED article. youtube.com/watch?v=YWL1TT…

Had a fantastic lesson today with one of my S2 classes. They worked well together and showed through the iodine clock experiment how concentration can have an impact on the speed of a reaction!! @StAmbroseSci @SSERCofficial #Inspire #sciencerocks #STEM #inspiredbysserc

This is my potato cell clock. The googly eyes were done in Photoshop (but I want to get some real ones for when I use this on class). Designed with @tinkercad and 3d printed in PLA.

@MrShortFHS_sci the first is a polyurethane foam kit (with food coloring). Second is good old PVA slime. Third is a demo I created using a PET bottle (pubs.acs.org/doi/10.1021/ac…). The last one is dissolving styrofoam w/ limonene (instead of acetone) and starch w/ water.

@alfmateus No! What are they?! Lemonello? What’s the foamy one? ….and pliers? 😂looks good. We have acetone/polystyrene, paginate worms…edu.rsc.org/experiments/cr…

Today the students explored several polymer experiments... Do you know them all?

Yesterday the students did a rotation that included the salt + ice + wet thread experiment. Always good when there's a surprise in the end.

Have you ever done the evaporation races? 2 liquids compete and the sts discuss the intermolecular interactions and their relative intensities. I've made this board using laser cut MDF. You wet cotton balls with each liquid and make a trace. Water x ethanol x i-propanol x acetone

@KatyDornbos I'd expect a difference related to the number of particles released when the salt dissolves. Sodium carbonate (3 particles) should be better than sodium chloride (2). But I'd not expect a change based in cation used. You use the same mass of each salt? Or moles?

@CummingsLinda @ChemEdX no, it is not the link.

@alfmateus @ChemEdX chemedx.org/article/simple…

A simple device used to demonstrate and clarify some challenging concepts in thermodynamics at the General Chemistry level is described. bit.ly/ThEqX

@hankgreen You will certainly not fix the housing problem with houses. But american cities don't let people build large, tall apartment buildings anywhere. Huge houses everywhere, for just one family.

I think a harm of online activism is the "THIS IS ACTUALLY EASY" argument. I've seen lots of folks indicate that a single billionaire could solve homelessness, or that there are 30x more houses than homeless people so we could just give them all houses. These words are fantastic for activating people, but they are also lies. The US government currently spends around 50B per year keeping people housed. States, of course, have their own budgets. If Bill Gates spent the same amount of money the US does just to keep people housed, he would be out of money in 3 years. I think that would be a great use of his money, but it would not be a permanent solution. The statistics about there being more houses than homeless are just...fake. They rely on looking at extremely low estimates of homelessness (which are never used in any other context) and include normal vacancy rates (an apartment is counted as vacant even if it's only vacant for a month while the landlord is finding a new tenant.) In a country with 150,000,000 housing units, a 2% vacancy rate is three million units, which, yes, is greater than the homeless population. But a 2% vacancy rate is extremely low (and bad, because it means there's fewer available units than there are people looking to move, which drives the price of rent higher.) Housing should not be an option in this country. It should be something we spend tons of money on. It should be a priority for every leader and every citizen. it should also be interfaced with in real, complex ways. And it should be remembered that the main way we solve the problem is BUILDING MORE HOUSING, which I find a whole lot of my peers in seemingly progressive spaces ARE ACTUALLY OPPOSED TO. Sometimes they are opposed to it because they've heard stats that the problem is simple and could be solved very easily if only we would just decide to solve it, which is DOING REAL DAMAGE. By telling the simplest version of the story, you can get people riled up, but what do you do with that once they're riled up if they were riled up by lies? There are only two paths: 1. Tell them the truth...that everything they've been told is actually a lie and that the problem is actually hard. And, because the problem is both big and hard, tons of people are working very hard on it, and they should be grateful for (or even become) one of those people. 2. Keep lying until they are convinced that the problem does not exist because it is hard, it exists because people are evil. Or, I guess, #3, people could just be angry and sad all the time, which is also not great for affecting real change. I dunno...I'm aware that people aren't doing this because they want to create a problem, and often they believe the fake stats they are quoting, but I do not think it is doing more good than harm, and I would like to see folks doing less of it. One thing that definitely does more good than harm is actually connecting to the complexity of an issue that is important to you. Do that...and see that there are many people working hard. We do not have any big, easy problems. If we did, they'd be solved. I'm sorry, it's a bummer, but here we are.

I am in London for a few days. Today I went to the natural history museum, a lovely building (if a bit cold) and a very nice collection. I plan to visit the Royal Institution and the Faraday museum tomorrow.

@Andrestrujado @Ri_Science Love these experiment filled lectures by Andrew Szydlo! Thanks for the link.

The perfect end of the year gift: Andrew Szydlo's latest demo lecture @Ri_Science all about the yellow element sulphur. 🌋🔥 A tour de force full of wonder, history of science & experiments galore. #brimstone #volcanoes Watch it here 👀 youtu.be/3cwcekm6wDQ?si…