字幕表 動画を再生する 英語字幕をプリント Periodically, I look at the periodic table and think - that’s not very well designed. Like, look at this big tall column on the left, and then a big gap, and then more tall columns on the right. And this island of elements down here, totally disconnected from the rest? It doesn’t feel very natural - so let’s rearrange the table! Obviously we don’t want to ignore physical reality, but the idea of the periodic table, roughly speaking, is that atoms are listed horizontally according to increasing atomic number and grouped vertically according to shared properties, so these breaks here on the left and right, where it goes from element 10 on the right to 11 way on the left - those are artificial. We should really be cutting the periodic table out and then taping the edges together, into a nice loop. Kind of like how there isn’t actually a giant disconnect between Russia and Alaska, even if maps make it seem like that. Anyway, once you join the Russia and Alaska of the periodic table, it makes a different location seem like the obvious place to cut if we really want a flat table - right here. Then we get the left-step periodic table, where the columns are all nicely stair-stepping down, though really it’s even nicer if helium moves up above beryllium and next to hydrogen where it so obviously belongs. This way of organizing the table looks really nice and makes a fair bit of sense from a physics perspective , even if it doesn’t have the nice properties of normal periodic tables where electronegativity and first ionization energy increase from left to right and bottom to top. But really, the periodic table should be a loop. The problem is, we still have a gap between elements 20 and 21, maybe we can loop them too? And what about 4 & 5? If we join them, we have a nice spiral periodic table, with no gaps between any of the numbers! Though it’s even nicer if helium moves over above neon where it so obviously belongs. This version kind of looks like a tiered cake, and goes really well on top of pointy trees! Except in this table, elements with similar properties aren’t grouped together vertically anymore. So we could attach the ones that are supposed to be grouped vertically, which forces us to make some folds, and now we get this spiral rosette-y periodic table, sometimes called “Mendeleev’s flower.” This really shows the structure of the table nicely, though it’s not really a table any more, and it’s way too three dimensional for a lot of uses. So let’s unspiral the spiral, and go back to basics - the one dimensional periodic table. It’s actually pretty long - look at all those elements! And it’s a lot harder to see the structure, though you can still see that certain properties repeat periodically - hence, periodic table. And if you match up those repeated patterns, and cut in all the right places, and do some surgery , you arrive back at the familiar - if not super elegant - traditional periodic table. Which table do you prefer? This video was supported by Brilliant, which is also a brilliant holiday gift for anyone who’s interested in math, science, puzzles, or cutting up periodic tables. Brilliant premium gets you or whoever you’re giving it to full access to all of brilliant’s courses, quizzes, puzzles, & daily challenges, including this one which is about cutting up hexagons into pieces and rearranging into other shapes with the same area. Or Brilliant’s course on chemical reactions, which’ll help you understand what you can and can’t make out of all the elements on the periodic table, or why some reactions are so explosive. To get good at science or math or just keep your mind sharp, there’s nothing better than regular and fun problem solving, and brilliant has you & your loved ones covered. Go to brilliant.org/minutephysics for a gift subscription to lifelong learning. Again, that’s brilliant.org/minutephysics, and thanks to Brilliant for their support.