Andrea Chlebikova

In #MathsToday, while the teams work on the shuttle rounds, we get to have a look at the short-listed posters on Voronoi diagrams. @ukmathstrust.bsky.social

Photo of me inside a frame stating "I attended the UKMT National Final".

Looking forward to today's @ukmathstrust.bsky.social STMC National Final in Manchester! Good luck to all the teams taking part 😀

I've spent the last week writing questions on symmetry in 3D (as this is important for chemistry) and being somewhat annoyed about how that isn't really taught in maths at all, so I feel your pain in a different way 😅

Yes, exactly. They're called dimensions for a reason!

Just remembered this fun question a colleague of mine wrote with an unusual set of base quantities! isaacscience.org/questions/al...

But as I've pointed out, you don't need those specific 7 things: you can create an equivalent basic set by, say, using charge instead of current, and molar mass instead of amount of substance. You could even go wild and replace length and time with speed and acceleration...

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Also worth noting that the choice of base quantities is not unique/a property of the universe and the things in it, but rather a somewhat arbitrary choice we have arrived at because of lots of history of science baggage.

E.g. we could have had charge rather than current as a base quantity.

I understand your intention, but that is not how "quantity" is used already! Everything is a quantity...

The amount of substance is also not in practice established by counting in any normal chemical context.

Oh no. We get enough hesitancy around the word "amount" given in everyday contexts that is used to mean mass or volume frequently. "Quantity" would be even worse!

It is (for a fixed substance, at fixed conditions, etc) not independent, but then (for a fixed substance, at fixed conditions, etc), neither are mass and volume independent from one another.

Screenshot of unpublished question on Isaac Science platform, titled "Not Just a Number?" and classified as Chemistry, Founda­tions, Numerical Skills Status, Not started Stage & difficulty, A Level Practice 2 Intro text reads: "In 1971, the mole was added as an SI base unit. However, this was not without controversy which continues until this day, with some arguing that the mole is just a number. Indeed, when students are first introduced to the mole, it is often introduced as being "a chemist's dozen" with analogies to other counting units (such as a ream of paper) drawn. In this question, we will explore why the decision to include the mole as a base unit was made, providing both a historical background and a modern context to why we chemists continue to use the mole." Part A is labelled History Part B is labelled SI base unit Part C is labelled Modern chemistry Attribution says "Created for isaacscience.org by Andrea Chlebikova"

Oh no, now the mole is facing attack from mathematicians, not just chemists! 🙉 Haha, I wrote a question on this (not yet published) last year...

The quantity is "amount of substance", by the way, the mole is the unit.

It's a bit "Ceci n'est pas une pipe"-esque, really. The number is not the thing.

Infographic titled “Snowflakes: Classifications & Shapes” showing how snowflakes are categorized by crystal form. Sections illustrate column crystals, plane crystals, combinations of column and plane crystals, rimed snow crystals, aggregation, germs of ice crystals, irregular particles, and other solid precipitation. Each category uses simple blue icons with codes (e.g., C1, P3). A key explains three classification levels: 8 general, 39 intermediate, and 121 elementary categories, highlighting the wide variety of snowflake shapes found in nature.

Getting snow where you are? Did you know that there are 121 categories of snowflake? ❄️

This graphic is an old favourite which gives an overview of the 39 intermediate categories: www.compoundchem.com/2014/12/10/s... 🧪

Merry Christmas to everyone who celebrates! 🧪

Infographic on the chemistry of Christmas puddings. The graphic shows the chemical structures of tartaric acid (from raisins) and citric acid (from citrus peel). It also explains how the custom of hiding small silver coins in the mixture is not advisable with modern coiins due to their nickel content.

It's Christmas Eve and the final day of #ChemAdvent!

We're finishing off with Christmas pudding and why you shouldn't hide a coin in the mixture as was customary in the past 🪙

#ChemSky 🧪

I learned a fair bit while writing this question about candles (part of our festive calendar of questions) the other week. Check it out if you want to learn a bit too! #ChemChat🧪

Oh no! Hope you have a good time nonetheless. Planning to drop by tomorrow.

Always great fun, with the likes of @algebraist.bsky.social and @heerpal.bsky.social!

How do Christmas crackers work? Test your chemistry knowledge and skills while learning some history of chemistry: isaacscience.org/questions/ch...

#ChatChemistry #ITeachChem #RealTimeChem #EduSky 🧪

Spend a merry moment or two pondering this moments question: isaacscience.org/questions/me...

#ChatPhysics #iTeachPhysics #SciTeachUK #EduSky ⚖️

Thank you to all of our student and teacher users, you have reached 200 million question attempts!

#SciTeachUK #EduSky

Today's question uses the core GCSE and A Level Chemistry skill of calculating empirical formulae on two compounds responsible for the bitter taste (to some!) of Brussels sprouts: isaacscience.org/questions/bi...

#ChatChemistry #ITeachChem #RealTimeChem #EduSky 🧪

Infographics on the chemistry of chocolate smell and the flavour chemistry of green bean casserole. The two are linked by the presence of earthy pyrazines.

Infographics on the chemistry of chocolate smell and the flavour chemistry of green bean casserole. The two are linked by the presence of earthy pyrazines.

A bit late kicking off #ChemAdvent day 1, but here we are!

This year I'm finding chemical connections between some previous ChemAdvent editions 🧪

First up, earthy pyrazines are the connection between the smells of chocolate and green bean casserole 🍫

Screenshot of a Christmas tree-like shape made up of a rectangular, brown block at the bottom, green-coloured hexagons arranged in a tree shape and a grey star at the top. Each hexagon contains a number: the integers from 1 to 24. The hexagon numbered 1 is coloured purple, the colour used for physics questions on the platform.

Every day of December, in the lead-up to the Christmas holidays, we will be posting a seasonal question from our platform.

The questions will be linked to from: isaacscience.org/pages/202512...
#ChatPhysics #iTeachPhysics #SciTeachUK #EduSky🎄

A painting of a house by one of Charles Darwin's children. We see a simple outline of a house with a pitched roof, two chimneys and some lead-paned windows. We see the kitchen fire, with a clock on a mantle, and some cast iron pots on a window sill. In a window at the stop of the house we see a cat, or possibly a squirrel!

A hand-written page of Charles Darwin's original manuscript for the Origin of Species. There are many ink blots and crossings out, and some foxing consistent with its age.

#OnThisDay in 1859, Charles Darwin's On the Origin of Species was first published.

Much of the original manuscript was used as scrap paper by Darwin's children. On the back of this painting of a house is an original manuscript page from Origin!

#CambridgeUniversityLibrary (DAR 185)

This talk was in the Ray Dolby Centre (the new Cavendish lab) and doing chemistry demos in a new physics building is always a bit more complicated without dedicated prep rooms, technicians, etc😀

(I will be doing some IA lectures in the BMS LT from 2027, so plenty of time to prep fun demos!)

And finally a guncotton Guy Fawkes effigy. #RealTimeChem

Burning a guncotton bird. #RealTimeChem

Happy bonfire night!

Enjoyed giving a quick talk about the science of fireworks at the Ray Dolby Centre tonight. Since I couldn't do the live demos there, they were pre-recorded in the morning, so here they (see comments) are for everyone's benefit!

#ITeachChem #RealTimeChem #EduSky #ChatChemistry

Teachers! View our Competitions Calendar and sign up here: ukmt.org.uk/competitions

#MathsToday #UKMT #MathsCompetitions

Applicant webinars 2025 St Catharine's College is collaborating with Brasenose College (University of Oxford) to deliver a series of free webinars in 2025 for students thinking of applying to the Universities of Oxford or Cambridge in 2026. Outreach staff will be delivering sessions with Oxbridge academics and students to:

We're hoping to avoid any interview horror stories this Halloween 👻 We've teamed up with @brasenoseoxford.bsky.social to host 11 online interview workshops 3–17 November for anyone applying to @cam.ac.uk or @ox.ac.uk for undergraduate courses. Find out more & sign up:

In #MathsToday, welcome to Bluesky, @ukmathstrust.bsky.social

Looking forward to seeing some of you at the upcoming TMC development weekend 😃