Mercury Shouldn't Be Liquid. But It Is.

[@y_fam_goeglyd]

Funny how Einstein solved two "mercury" problems. This one, and the Mercury "glitch" in Newton's Theory of Gravity. Complete coincidence, I'm sure, but it's interesting to me at least.

[@theheadone]

I was thinking this as well and I was surprised he didn't mention it considering he was a host on the former space scishow.

[@icollectstories5702]

Well, the other Mercury required General Relativity because Special Relativity just wasn't enough.😁

[@carultch]

It's probably a lot less of a coincidence than you think. The namesake of both Mercuries is the Roman messenger god, and the reason they both are named after him, is swiftness. Mercury the planet being the fastest moving planet in the sky, and mercury the element being the element that flows fast as a liquid at room temperature. They both have being fast for their class in common, that earned them both the same namesake, and it is their speeds that cause relativistic effects to come in to play.

[@JarrodFrates]

@@carultchThe planet Mercury doesn't move fast enough for relativistic effects to come into play. Its average orbital speed is about 47 km/sec. General relativity comes into play for Mercury's orbit because the Sun's gravity warps space enough to affect Mercury's orbital precession. Every planet, and indeed every body orbiting the Sun is affected in a similar way, just less strongly than Mercury. Edit: As a couple of people have pointed out, I mistakenly wrote special relativity when I meant general relativity. Thanks for the corrections.

[@carultch]

@@JarrodFrates Still, it moves fast precisely because it is in a position where the sun's gravitational distortion of spacetime, is enough for relativistic effects to come into play. You wouldn't expect Uranus to have anomalies in its orbit that were explained by relativistic effects instead of another planet, when its orbital anomalies were used as a clue to discover Neptune.

[@LeonMRr]

Another interesting application of SR to atomic orbitals is in the color of gold. Metals usually don't absorb the photons of visible light they receive, instead they are scattered elastically. But in gold, electrons are moving at around 0.5c so their "mass" is changed, which changes the energy required to excite them from one shell to another, and that change happens to make the gold atom absorb more blue light, turning gold yellow to us.

[@McKaySavage]

That’s another cool example of SR in chemistry. Thanks for sharing!

[@LuisAldamiz]

Interesting trivia.

[@SeedlingNL]

@@McKaySavage I think it's also the reason why higher elements become more and more unstable... those speedfreak electrons literally twist spacetime so much that the atom itself is being ripped apart... the Roche limit of subatomic scales...

[@naverilllang]

What about copper? It's a much lighter element

[@MrHowzaa]

i heard its red shifting the light.

[@martijn8491]

Just wow! I have an MSc in Physics and it's just amazing how you were able to explain so much pretty complicated physics in such a short video without too many shortcuts and without missing some important nuances and while keeping it understandable for the general public. And I also learned something interesting and new. I watch all scishow videos, but I'm seriously impressed by the quality of this one!!!

[@kathrynthomas6390]

I'm a bio major and this one really actually felt intuitive!

[@pencilpauli9442]

Even I could follow the explanation. Grade D "O" Level Physics (twice) ie failed twice to get the minimum C grade that is recognised as a pass.

[@marckyle5895]

I was wishing I had science teachers like this.

[@robertfitzjohn4755]

DPhil in Chemistry here, back in the 1980s. My reasearch involved the energy levels in uranium compounds (92 protons and electrons) so I'm familiar with d and f subshells and relativistic effects in the core orbitals, which I thought were explained well here. My work was primarily experimental and my theoretical model was just a simple one involving only the outer electrons, but since then people with powerful computers have done the relativistic calculations and come up with answers that explain the experimental results.

[@pyrotas]

If you have a degree in Physics you should know that mass does not change under Lorentz transformations but it is a scalar invariant and hence all this video makes no sense.

[@Dommi8450]

I graduated in 1999 and subshells were not taught to me. I had to look up a different video that explained that it is introductory chemistry. It was a weird feeling that something so basic to younger kids/teens is completely new to me.

[@ajchapeliere]

I remember a game show based loosely around that situation. I also remember arguing with my grandma about how lightning works because the knowledge and information access in her school years were more limited. I also still get tripped up by the knowledge that plate tectonics wasn't scientific canon until the 1960's or so. It just seemed so.... "It is known" by the time I was learning it, but it's contemporary to the US civil rights movement. Perception of time is wild.

[@qazsedcft2162]

I was in college around that time and it was definitely taught in the university intro chemistry class. In high school we only ever had the Bohr model simplified stuff.

[@solconcordia4315]

I was hardly taught about subshells, either, in the U.S.A. I think that our professors considered them as inaccurate and outdated concepts in deference to the boundary-condition-induced quantum numbers so we got the atomic orbitals expositions. I, however, was precocious so I had already learnt that from my Big Brother's collection of textbooks he had used. The Chemistry textbooks used the subshell models pretty effectively to explain chemical engagement between atoms. As I have a historical perspective, I tolerate thinking of electrons of atoms being packaged into subshells. After all, the Madelung (n+l) rule used by the Aufbauprinzip maps atomic subshells with electronic configurations' filling order pretty well (but not quite right all the way -- I'm not a chemist so I know anyway that I shouldn't trust my *historic* chemistry education 100%: trust *AND* verify.) Electrons are delocalized waves as well as like tiny hard nuts. It just depends upon the resolution with which one looks at the electrons. In superconductivity research for room-temperature ambient-temperature superconductors, electrons should be thought of as being delocalized waves (viz. Bloch waves) capable of being decomposed into Fourier series with a periodic coherence length that can extend its range to near infinity to achieve resonance.

[@dreammaker9642]

Took me to first or second year of uni to finally understand. Think is you aren’t taught the Heisenberg model or principle of uncertainty till then because the Borr model gets taught instead as it’s easier to understand and works for the purpose intended. To be fair skipping the borr model would make it hard to understand Heisenberg

[@dreammaker9642]

@@qazsedcft2162cause that’s all you needed. Bohr model is “wrong” but it works for the purpose intended and it’s easier to understand. I doubt you could easily understand the Heisenberg model if you don’t understand and work with the Bohr model. Unless you make the mistake of entering a organic chem class then it doesn’t really matter that much.

[@galliumgames3962]

If mercury had a higher boiling point, it would be FAR safer to play with. Mercury metal is closer to a noble metal than not and in of itself is much lower toxicity as an elemental material. However, its vapor pressure is high enough to not be negligible and the vapor is extraordinarily toxic as it has essentially unlimited surface area to do no no chemistry in your body when inhaled. Edit: Liquid mercury in its own context should probably still be considered at some level of hazard as very small amounts (Generally considered negligible in most circumstances fortunately.) can be absorbed in the GI system and the beads can finely divide and get stuck in crevices such as your fingernails, as well as internally if swallowed. Metals such as gold and platinum are also pretty toxic outside their metallic forms, but do not have the same problems of producing vapor or being a mobile liquid at room temperature. If you do intend on playing with mercury, do so in a ventilated area, account for any possible escaping material and wear gloves, or at least throughly wash your hands after handling. Spilt mercury can get into cracks in furniture, walls and the floor and will take years to evaporate. The vapor pressure of mercury at room temperature is 0.25 Pa and this is 200x the maximum permissible 8hr exposure levels by OSHA. Mercury vapor can build up to toxic levels from spills in enclosed environments, this is why the fire department takes it so seriously.

[@margodphd]

I wheezed at " no no chemistry". Since today, this is the new, improved title of my toxicology books 😂

[@queefyg490]

Liquid at room temp basically means there will always be vapor regardless if it's reached it's boiling point. Melting easily and boiling easily are basically due to the same thing although you still have to factor in polarity.

[@bariumselenided5152]

"No no chemistry" will forever live in my mental dictionary now

[@fukpoeslaw3613]

No chemistry?! What the fu... oh, 'no no' oh ok.

[@galliumgames3962]

@@queefyg490 Gallium is weird though, with an utterly massive liquid range and boiling point of 2,400°C. IIRC the vapor pressure of gallium at 30°C is so low that it’s a probability of there being a single atom as opposed to a definable pressure value.

[@pgc6290]

The fact that you ask to 'recall' high school chemistry makes me feel really good.

[@jessi411]

Started the video, got confused, Googled some things, kept playing the video, went back to Google... now my boyfriend and I are having heated discussions about how to visualize and understand the dimensions of the universe. 10/10 that's the sign of good educational content

[@csvscs]

Healthy comment! 🎉

[@Atticusdoesthings]

I wish I had heated discussions about the universe with my partner

[@neerajwa]

Higher dimensions eh ... Talk to some Hilbert space dweller

[@LuisAldamiz]

Best is to remove one spatial dimension (or two) in order to allow for the remaining axis to represent time.

[@donwald3436]

I'm jealous lol.

[@andriypredmyrskyy7791]

I've been curious about this topic forever, and your scientific communication was so top notch I felt compelled to tell you about how good it is. Having undergrad under my belt helps a lot but this was really easy to understand.

[@clipsdaily101]

i grew up thinking there was nothing left to discover. Aristotle- "The more you know, the more you realize you don't know"

[@aamirrazak3467]

Agreed seems like the more knowledge you acquire, the more questions you have

[@dustind4694]

Every question answered should lead to at least one more question unanswered, but typically two or more.

[@markloveless1001]

Dunning-Kreuger, thy name is law.

[@somebody-anonymous]

Also Aristotle: The velocity at which an object falls is proportional to its mass

[@donhoverson6348]

The puzzles of Dark matter and Dark Energy still loom pretty large. Likely I will never see those solved.

[@BaronVonQuiply]

Too hazardous to keep around, I've replaced all mine with quicksilver. **dies confused**

[@thenexttangle8568]

It's another name for Mercury

[@michaelhaywood8262]

@@thenexttangle8568 I think BarononQuiply knows that His was a joke comment.

[@thenexttangle8568]

@@michaelhaywood8262 oh My bad

[@dustind4694]

"Let's start in the shallow end of the pool... Which I filled with **water**, not mercury" - Things you can absolutely expect science profs to say, both to reassure people and to bemoan the necessity of ethics.

[@olmostgudinaf8100]

And cost. I have a hunch that a pool of mercury might be ever so slightly dearer than a pool of water.

[@dustind4694]

@@olmostgudinaf8100 One can assume that any science prof is going to be upset about the budget (this is a touch more reasonable than being annoyed you can't show off cool and dangerous things).

[@samstromberg5593]

Dearer? Does that word have a definition I don't know about or was that a typo?

[@olmostgudinaf8100]

@@samstromberg5593 Not a typo, as any search engine can tell you.

[@dustind4694]

@@samstromberg5593 It's typically more of a British English thing (not exclusively), but much as something can be loved dearly, it can cost one dearly, or be sold dearly. A dearer price is high or expensive.

[@thefaboo]

"... the more massive they *measure you* to be..." Side-stepped a whole physicist flamewar there 😂

[@robfut9954]

Went over my head, please explain. Why is that controversial

[@omgsrsly]

@@robfut9954 Because the mass is not increasing in reality, although it is used as the most common explanation.

[@rtg_onefourtwoeightfiveseven]

I was about to head to the comments section to be all "um acktchually" but I stopped because of that. Good save on his part.

[@thefaboo]

@@omgsrsly @robfut9954 and the flamewar part is that there are a lot of working physicists who prefer the original interpretation....

[@AsmodeusMictian]

@@thefaboo This will forever baffle me. Science is all about replacing old information that's discovered to be incorrect with new, *proven* information so that we as a species can progress in our understanding of the worlds around us. To just reject new information smacks more of religion than science to me. You don't arrange your theories to come into line with reality, you re-arrange reality to come into line with your beliefs. No thanks. Stopped that decades ago now :D

[@Atticus_Loves_Lacquer]

My grandmother once told me that they used to play with Mercury like sensory slime as kids ☠️☠️☠️

[@donaldpetersen2382]

You cant absorb it though your skin, nor will it leave any dangerous traces.

[@Atticus_Loves_Lacquer]

@@donaldpetersen2382 quick skin exposure is one thing, but children playing with it unsupervised for hours on end I think that’s in unsafe territory based on the little but informative research I’ve done. 🫶

[@Fazzel]

When I was in 5th grade I was in safety patrol and another kid used mercury he got from his dad to keep his badge shiny.

[@davemeise2192]

We used to play in it with our fingers during our science class. I remember how heavy it was when poured into the palm of your hand. Cool stuff!

[@daizy7441]

⁠@@donaldpetersen2382i mean, you usually can’t, but that doesn’t make it *safe*. it can get in through any minor, imperceptible cut or scrape not to mention room temperature mercury can evaporate slightly and that’ll really mess up your insides if you inhale it too much or too often

[@kwokchuchan7793]

As a PhD in Chemistry I understand why mercury is unreactive, but I didn't understand how relativitistic effect turned mercury into liquid. Now I understand. Thanks for your simple but excellent explanation!

[@KingsleyIII]

The Chinese guy who drank mercury thinking it would grant eternal life was _dead_ wrong.

[@aamirrazak3467]

Yeah I’d imagine it didn’t work out well for him

[@arya_1503_fancade]

ba dum tsss

[@VenThusiaist]

literally

[@anthonymotture]

Dead wong

[@ppoad]

Or depending on his believes he may enter into the eternal life realm… 😂 so he could be right!

[@jmackmcneill]

4:19 I think of chemical reactivity as atoms being sociable and extroverted, but equally I understand having all your electron shells filled must be a very cosy and reassuring feeling.

[@mikemondano3624]

It's suffocating, actually. It makes one long for extinction in the wave function of a large, copper conductor.

[@zdlax]

I think I read somewhere that another consequence of SR is gold having the color it does as opposed to a standard metallic color.

[@Eden_Laika]

Yep, SR shifts the absorption spectrum of gold down into the visible spectrum, meaning it absorbs blue light but reflects red and green light giving it its yellow colour. The details are complicated but have to do with SR effects chaging the resonance frequency of the outer valence electrons.

[@stevesmith2044]

Gold maximum phenomenon

[@StuffandThings_]

It also gives it unusually high electronegativity for a D block element, to the point where it can even form anions, due to the relativistic speeds reached by the valence electrons

[@davidaugustofc2574]

​@@Eden_Laika wouldn't SR redshift the light that Gold reflects? Gold is very good at reflecting Infra-Red and very bad at Reflecting Blue

[@Eden_Laika]

@@davidaugustofc2574 Only if the gold was moving away from the observer. Red shift isn't a property of a material, but of relative velocity.

[@RogerTerrill]

Thanks!

[@KenLord]

cant believe that a video talking about how special relativity is required to understand the behaviour of the element mercury due to its impact on orbitals ... didnt mention how special relativity was required to explain the orbit of Mercury (the planet).

[@xyex]

Haha, that didn't even occur to me. 😂

[@annaclarafenyo8185]

Special relativity doesn't explain the orbit of Mercury, General Relativity does. Special relativity gives a negligible correction.

[@Relkond]

General relativity is also why gold is yellow. Without it, gold would be a boring, silvery color. It does a lot to make the world more interesting.

[@oracleofdelphi4533]

Can't blame special relativity for the aftermath of a Taco Bell meal.

[@Pho7on]

@@Relkond Special relativity is what explains the color. It's a similar effect as in mercury.

[@objective_psychology]

Tfw Einstein solved a Mercury mystery AND a mercury mystery

[@skeeterinnewjersey5256]

Put this together with Hank's chemistry CRASH Course and you have a basic college course in physics. And it's understandable.

[@Verschlungen]

Ever since observing HgO powder turn into liquid mercury + (invisible) oxygen in a high school chemistry demonstration in 1960, Hg has been my "favorite element." Now, with your ability to take an abstruse topic (SR) and give it the explainlikeimfive treatment, you've made Hg even more magical for me, at age 80. Thank you!!

[@BeepBooper55]

me hearing "It maybe toxic but sure looks magical" from youtube autoplay and just thought, sounds like my ex 😅🤣

[@Makabert.Abylon]

There is good just rightly offensive joke there someone just needs to work it out. It has to start somewhere.. Women are like the elements of the periodic table, the more beautiful, the more toxic.

[@kitcutting]

“… Like a Ferrari with no engine. Fine as hell, but it just sits there and costs me money”

[@kitcutting]

@@SimuLord SEE, your ex was like the alpha particle, mine was like the Big Bang. Incredibly hot… and just as dense

[@NinjaRunningWild]

Pretty much most people’s ex.

[@Andytlp]

@@NinjaRunningWild If you like a person you dont just be nice to them. Otherwise you wont see their worst side

[@feynmanschwingere_mc2270]

Einstein is the GOAT...Funny thing is he came up with special relativity 2 years after essentially doing J.W. Gibbs historically famous work (but Gibbs's seminal work in thermodynamics/statistical mechanics) hadn't been translated to German yet. Oh and Einstein independently discovered the Raleigh-Jeans Law and several other laws in physics are named after other people even though Einstein discovered them first (e.g. Probability Waves being one of them - as Max Born always acknowledged in his letters). Not to mention Schrodinger definitely doesn't discover his famous wave mechanics without Einstein's help. The man was next level brilliant. Even Dirac was in awe.

[@markloveless1001]

My dad gave me an aspirin bottle half full of mercury he got out of washing machine lid contact switches (the 60s were a simpler time). I remember pouring it from hand to hand. Didn't effect me at all (tic) at all (tic) at all....

[@y_fam_goeglyd]

😂😂😂

[@Jefuslives]

I think we had the same dad.

[@fumfering]

I broke a thermometer when I was a kid who couldn't stop fiddling with things way back when they actually had mercury in them, and have always wondered how much of my personality is a result of playing with the little shiny balls rolling around on the tile floor...😮

[@casjean8904]

@@fumfering same here! nowadays they call for a hazmat crew.

[@markloveless1001]

@@Jefuslives I was too young to remember, but my older cousins told me when they buried my grandfather, they had to use dynamite (which was available at the farmer's co-op when Dad was a kid), and we were given lengths of fuses to play with. Light one end and when it got to the other, small bang.

[@alden1132]

I was very recently explaining this in a comment thread concerning liquid metals and mercury, specifically. It's a fascinating quirk of physics, and always makes me wonder what other unusual properties re: the behavior of matter might exist. This is the only example of this type t that I'm aware of, but there MUST be others...

[@HappyBeezerStudios]

Copernicium, the element below mercury in the periodic table is also assumed to be liquid at standard temperature and pressure. We just haven't made enough to observe that.

[@alden1132]

@@HappyBeezerStudios That's interesting. I had never heard that! I love trivia.

[@FSAPOJake]

This might be one of the best explanations for a relatively (pun intended) complex topic in this channel's history.

[@marckyle5895]

The way he _generalizes_ makes me feel _special_

[@wheelie157]

all made possible by post malone's brother too its crazy!

[@markmathews2143]

This was a really good explanation that takes a complex idea like valency and electron shells, and completely explained several complex topics with the required detail to make it understandable to laymen and hobbyists. Even my son understood it and he struggles with science. And if they have any questions, they should go see Hank over at crash course, another excellent series that you should link to in the description as videos like this with an easy to understand follow up intro course makes science topics accessible to everyone. Good job.

[@kharris274]

I have a question… if the more proton make some atom becomes less reactive, then why does galium also has a liquid phase on room temperature? And why we don’t have more metal that’s liquid in room temperature for higher atomic numbers

[@yar3333]

Ga has an electron in an outer shell. Look at group 12. Also note that "room"/"not room" temperature is just a constant. For nature 0 and 200 degrees are not that different (add 273, the absolute zero, to both of them).

[@robertdyson4216]

Very good. It’s rare that I hear someone say ‘negative’ for a number value rather than the operator 'minus', but I always do. On the wave/particle duality I find it best to say that these entities behave sometimes like waves and sometimes like particles, it’s not that they are both. You graphic for special relativity is what people usually show for ‘curved’ space-time in general relativity. I must look up the 2013 simulation. It will have needed some simplifications even to get that result, I am sure people will have another go sometime to get nearer.

[@PierreVB-514]

Great presentation 🙂 Next step , maybe you could come up with an a grounded explanation as to why technetium is one of the few elements of the periodic table of elements that isn't stable despite its low atomic weight.

[@thomicrisler9855]

Yes! I've always wondered that.

[@HappyBeezerStudios]

Elements with even proton number also tend to be more stable than those with odd protons for some reason. Odd elements also have fewer stable isotopes. Looking at it there doesn't seem to be any weird situation, normal β+ and β- decay. But other higher elements in the 53 to 57 nucleotide range show α decay, which doesn't happen again until 83 nucleotides, at which point it starts getting increasingly common.

[@HowShouldIKnow6543]

Killer episode, the electron speed in the lower shells 😮

[@TheRedRave]

Little correction here, though it is often said like that, the 12th period, Zinc and under including mercury, are not transition metals as per the definition of what a transition metal is (see IUPAC color books). Being an element of the d-block, the middle of the table, doesn't mean they are transition metals, cause the 12th period ones are not.

[@skeeterinnewjersey5256]

You had to step all over it for us lay folk, didn't you?

[@goosenotmaverick1156]

​@@skeeterinnewjersey5256dude I didn't even understand the correction. Maybe I'm stupid, but at least it didn't ruin my fun 😂😂😂

[@crazy_mind-ox8if]

What are they considered then? An "other metal"? Didnt see any periodic tables with them labeled anything other than transition metals and I'm too lazy to try and find the IUPAC one you said.

[@McKaySavage]

Most periodic table sources still class it as a transition metal, while some combine it with the basic metals and call the group post-transition metals. In all honesty, the delineation isn’t enough of a mistake to call for a correction of the video’s efforts to educate, given the necessity to simplify anyway.

[@MarioFanGamer659]

This reminds me of the classification of hydrogen and the problems thereof which they made four weeks ago.

[@Juice1984]

I guess calling Mercury "Quicksilver" wasn't that far off.

[@smokeduv]

So the halogens are “sort of reactive”? They are most like if they were like the ones in the leftmost in reactivity but the noble gases sort of messes it up because those don’t react (mostly). Aside from that I love the video and the channel in general

[@eroraf8637]

Halogens are highly electronegative with a single valence vacancy, so they REALLY want that last electron. Noble gases have a full valence shell, so they’re happy as they are.

[@ksoman953]

It is so much more fun to think of electron clouds playing around in reactions between things to form, well cloudy bonds!

[@kbee225]

I was taught that the whole electron moving around the nucleus model is incorrect as there are some glaring issues with it. For one, it is a charge undergoing acceleration, it should be be emitting photons continuously till the energy of the electron decrease and eventually collapse into the nucleus. The quantum model uses the orbitals you mentioned and proposes that these electrons exist in a cloud of probability on these orbitals. So it is delocalized, i.e., it doesn't exist as a particle which takes up a location in space. So in this model, how does the velocity of an electron matter when you can never measure the location and the momentum of an electron simultaneously?

[@Tangarisu]

Yes because whenever we measure or observe the atom and its electron shells we are essentially "taking a snapshot" and freezing the electron in observable space so we can gain an ide and its spin and angular momentum.

[@goodmaro]

"Incorrect" models can still be correct for much of what they model, which may be the important parts. It still makes sense to model electrons as point charges and point masses, provided you allow such things as angular momentum of 0 in some cases, i.e. that point either passing thru the center of the nucleus up and down or taking a figure 8 course. It's just a limit of our imagination, not being able to hold contradictory models in our heads simultaneously. But we know it works, because of such applications as NMR.

[@FoxofWallstreet]

It doesn‘t. To be honest, I‘m fairly sure that the entire idea behind this video is wrong, as it is doing it‘s math with E=mc^2 which is not the correct formula for moving objects, the correct one would be E^2=(mc^2)^2+(pc)^2 or E=ymc^2 with y being the Lorentz-factor. Or for short: Relativistic mass isn‘t a thing. So for short: The video really wasn‘t onto something at all.

[@curiousnerdkitteh]

Great video, and I love Reid's energy and enthusiasm!

[@KidFury27]

I'm glad he identified that it must be -39 degrees Celsius.... Because at that temp F is pretty much the same 😂

[@Fazzel]

Yes, 40 degrees C and 40 degrees F are the same temperature.

[@zimriel]

@@Fazzel no joke, that's where I first learnt about linear graphing.

[@icedbear]

Units are important. There are more than two temperature scales.

[@giantsquid2]

@@Fazzel No. 40 deg C is 104 degrees F.

[@giantsquid2]

I think you mean -40 deg C is equal to -40 deg F.

[@altariacorona]

My lecturer in inorganic chemistry told us this when I was a bachelor's student (in chem). Fascinating stuff, I never thought relativity in that way. I still remember until today

[@erikjrn4080]

So, basically, it has built-in relativistic speeds. Whoever named it quicksilver had absolutely no idea how accurate they were.

[@GoldSkulltulaHunter]

The script of this video was superbly written (and read!). It went from basic to complex without patronizing or alienating any viewers. I also really enjoyed the way scientific models are treated as that - models, not a precise description of reality - and how it shows that even "wrong", simplified or outdated models can serve purposes in academia and education, despite their limitations. Kudos to the writer and the whole team!

[@RichardNeill01]

Mass is a Lorentz invariant. It is momentum (gamma m v) that increases relativistically.

[@4RILDIGITAL]

Special relativity affects not only space travel, but also chemistry, down to the very properties of elements. Very well presented.

[@mekosmowski]

So, why don't we see a similar effect in the rest of the period 6 transition metals? Gold and platinum are fairly malleable, but tungsten has arguably the greatest intermetallic bond strength based on a review of physical properties.

[@eroraf8637]

Remember what he said about the filled sub-orbitals? Tungsten doesn’t have those. The intermolecular forces are much stronger for tungsten. Remember, mercury is only held together by van der Waals forces, precisely because of its filled sub-orbitals.

[@mekosmowski]

@@eroraf8637 But they're all big enough they should also have the relativistic effects from the full f orbitals. So they all should be a bit shrunken and have greater electron density, so the should be more repulsive toward each other than their one up the group neighbor.

[@eroraf8637]

@@mekosmowski I think you've misunderstood. The full f orbitals and the relativistic effect are two distinct contributions. Also, they aren't the only things that determine an element's melting point or material strength as a solid. You also have to consider the overlapping of different orbitals and sub-orbitals due to charge shielding and other such effects, but I'm not exactly an expert on condensed-matter physics.

[@mekosmowski]

@@eroraf8637 I'm not asking why the other transition metals of the period aren't also liquid, but why they don't have reduced intermetallic bond strength compared to their group neighbors from one period above, for example gold compared to silver (which specifically does seem to have reduced bond strength as evidenced by greater malleability, but this might be more a factor of crystal structure). Sure, reduced atomic mass is expected to reduce the relativistic effects, but it doesn't seem like a dozen or so protons and neutrons would be enough for such a dramatic change.

[@eroraf8637]

@@mekosmowski Like I said, there are other effects beyond just what's discussed in this video. Look up relativistic quantum chemistry if you want to know more. I'm just an astrophysicist, and I never took any graduate-level quantum or chemistry courses, so this is way beyond my expertise.

[@GreatDivideSven]

This is a great video. Maybe it hit me at a time when I've been getting an interest in chemistry, but it explained well a lot of things that are not talked about every day. And got me to ask more questions

[@TheEternalPheonix]

1:03 Sorry dude, I emptied it back out and refilled it with mercury.

[@RR-in7do]

I've actually wondered this for years and this was by far the best explanation I've come across.

[@kevinjung6130]

The "Qin" in "Qin Shi Huang" is pronounced closer to Chin rather than Quinn or Kin. Great video!

[@pattheplanter]

Pinyin has some weird choices for pronunciation.

[@PADARM]

It's incredible how powerful Relativity is. It continues to give us solutions 100 years after being created.

[@AquibMohammedAyman]

It's not a liquid. It is a planet 😂

[@ZurigaSungama]

It's not a planet. It is a deity 😂

[@markloveless1001]

And the FTD delivery man.

[@KenLord]

coincidentally, special relativity was required to understand the behaviour of both the planet (it's orbit) and the element (it's orbitals).

[@azurius_]

@@ZurigaSungama its not a deity its the singer from queen

[@trdidion]

it’s also a car.

[@mr.boomguy]

This is what I find fascinating about atoms, both recently and in general. The way just a few connections can change a whole element with vastly deferent properties, not to mention molecules

[@johnford7847]

Seems to me they haven't "proved" anything. They need to run the same simulations on, say, gold and thallium, to show that the results are not an artifact of the differences in simulation methods.

[@zimriel]

that's hard to do with 80 protons. Maybe start small with zinc?

[@FoxofWallstreet]

Probably because the theory involves relativistic mass, which isn‘t even a thing anymore

[@MikkoRantalainen]

Great video! It would be interesting to have a follow-up video about why does Gallium have so low melting point even though it has much less protons than Mercury?

[@hddrown]

7:20 No, No, No, No. Mass does not change relativistically, relativistic mass is an extremely outdated idea that only adds to student confusion when learning relativity. If mass changed with velocity motion would no longer be relative, you would be able to distinguish which observer was moving.

[@FoxofWallstreet]

Finally somebody with an actual clue on special relativity.

[@StuffandThings_]

Another fun one is gold, which is remarkably electronegative due to relativistic electrons. You can even get gold anions, such as in cesium auride!

[@paulwalsh2344]

This was one of the BEST SciShow episodes EVER ! And that's saying a lot !

[@pascal6077]

This is by far one of my favorite scishow videos!

[@Lefty217]

0:36 I thought mercury was awesome when I realized it was the "switch" in the old home thermostats that still used tilt switch style controls. really cool stuff!

[@michaelmckinney7240]

What a wonderful presentation by Reid Reimers who very clearly and interestingly describes the behavior of the mercury atom. Reid doesn't teach so much as he invites all of us to learn together in this very effective tutorial. I don't like being taught but I love learning which is why I give this presentation very high marks. Thank you Reid.

[@Sparky-ww5re]

Mercury aka quicksilver indeed had some very useful applications. Old timers may remember the so called "silent light switches " famously made by GE, Leviton, and probably other manufacturers as well, with a 50 year warranty, these were available until 1991, and were most popular in the 1960s - 1970s for use in children's rooms, nurseries, libraries and similar areas where silence is golden. It was also used in switches for the trunk & hood lights in automobiles, and of course thermostats until about the early 2000s, around 2002. This is something to keep in mind if you're scrapping a vehicle that's more than 20 years old, although like many things, the dangers of mercury tend to be a bit overexaggerated. .

[@johnathonhughes4814]

I watch a lot of science videos but this one expanded my view of atomic theory by applying relativity to chemistry. Thanks so much!

[@AroundTheBlockAgain]

I love it when I learn that relativity and speed-of-light-problems can be close by and familiar to me. It's not just some weird thing that could theoretically happen to future space travelers speeding across the galaxy at significant-fractions-of-the-speed-of-light. It's in some very down-to-earth stuff like mercury and gold. Thanks for this video!

[@knutritter461]

M. Sc. of chemistry here.... a GREAT video and explanation! When we finally got to the point in our studies why it is liquid, why gold has a color and other elements have unexpected oxidation-states (inert-pair-effect), the explanation was mindblowing to us. Strongly contracting s-orbitals and only slightly contracting d-orbitals causing bad overlapping. Overlapping d-orbitals are just.... bad beyond recognition causing a bad metal bond. Thank you Einstein! 🤣

[@phillair3813]

Thank you for the clear explanation. As a retired science teacher, it's terrific to be in the know of something relativity can illuminate.

[@guruprasadr6743]

Traditionally we are taught to think that relativistic effects are of no consequence in conventional chemistry. I must confess that initially I thought the suggestion of relativity to explain the liquid nature as preposterous. As the video progressed I can only say that I continued to watch it in silent amazement. I guess this requires a re thinking of what we leant in schools and colleges. Thank you for opening a completely new perspective on this.

[@Leadvest]

It's crazy how approaching chemistry backwards from the van der Waals force creates such an intuitive cognitive model.

[@realcreative3334]

I was talking to a professor in inorganic chemistry at my uni last semester and he said pretty much exactly this, but followed it up with the fact that Copernicium, which is in the period bellow is would also be a liquid if we could observe it properly in room temperature

[@smartguy-lx9im]

Except we never will because a) it will very quickly decay into something that is NOT copernicium and b) the radiation released in doing so would kill/injure anyone watching and heat the sample so much it would vapourise. Understandably, most of the transuranic elements are somewhat mysterious and near impossible to study.

[@SuperiorDave]

This was one of my favorite episodes. I love chemistry. Thank you sci show.

[@unything2696]

My prof in computational chemistry explained relativistic effects in two sentences and we moved on. And it was indeed enough. Short and precise, enough for the moment. It wasn't the main topic of the lesson, but it was helpful to continue. (Coming from HF, taking a look at semi empirical methods going towards DFT.) I like the explanations giving in this video, they did a good job. It's all models anyway, don't forget that. Everything is relative;)

[@esmenhamaire6398]

Absolutely brilliant episode!. I've generally not been keen on this presenters presentation style, but in this episode couldn't find fault with his delivery.. The topic was extremely interesting too - one where both quantum mechanics an special relativity are required to explain something. I'd love to see a deeper dive on the topic!

[@Eztoez]

Beautifully explained. So clear and easy to understand.

[@h7opolo]

apparently contradictory ideas 8:35, claimed that electrons dont get closer to nucleus, but instead get faster, however at 9:00, the shells do contract.

[@Xanman64-p6q]

Subshells contract, not shells.

[@jmackmcneill]

They don't get close due to electromagnetic effect, the contraction due to mass is an S/T warping effect.

[@TheTruthPlease100]

Close but sounds like there are a few things we don't fully understand yet. Cool!

[@Hatecrewdethrol]

While i was taught the planetary model back when i was in high school (early 2000's) they also were very clear that to explain that: "atoms do not actually look like this, we have no idea what atoms look like because they're too small, but using this model to explain it aligns with how things actually react in experiments"

[@daryllwilson3708]

Excellent video. I wish 10% of KZbin had content half as good as this video.

[@SanchoPanza-m8m]

If you loved me half as much as I love you, you wouldn't worry me half as much as you do.

[@jeremypearson9019]

This is the first time I have ever heard anything about electrons in lower shells moving at higher velocities and that they can sometimes be subject to relativistic effects. This is incredible! Why didn't this ever come up in any of my college classes, or at least in any other popular science media? This seems to me like it's extremely relevant because it's a case where quantum physics and relativity work together simultaneously to describe an observable phenomenon.

[@FoxofWallstreet]

Because it is incorrect

[@michaelszczys8316]

I remember watching a movie in school about metals in which they took a test tube full of mercury, put a paper sucker stick in it and immersed in liquid nitrogen to freeze it solid. Then took a hammer and smashed the glass and commenced beating it out flat. It was similar to lead when in frozen solid state. Pretty cool.

[@XenonPrimeSBSV]

Absolutely fascinating, I never would have thought relativistic electrons would have such a significant impact on material behaviour we can see.

[@MathewSan_]

Great video 👍

[@MrBlaDiBla68]

Excellent approachable vid !

[@wavydavy9816]

When I was a lad I got a 'Mercury Maze' for Xmas.. It was interesting for about 5 minutes and later the same day my big brother helped me break it open to get the mercury out. Luckily, my Uncle was staying over and he advised my (cluesless) parents that they should dispose of said mercury in a sensible container before we decided to drink it. Sensible man 👍

[@garyfilmer382]

A great, stunning explanation! Thank you for this video.

[@asandax6]

1:39 Fluorine is laughing at the corner after being called sorta reactive.

[@MarsJenkar]

"Sort of reactive" for the halogens is a massive understatement. A lot of people quote John D. Clark's statements regarding the dangers of the compound chlorine trifluoride (a highly reactive compound made solely from halogen atoms), but less known is that in a later chapter of the same book he says basically the same things about molecular fluorine.

[@pauls5745]

I got very happy at the use of the emoji at 4:19

[@julianbrelsford]

As a kid growing up in a cold climate, i remember seeing a lot of thermometers whose coldest measurable temperature was lower than -40. Our coldest day ever in my town (during my time there) was colder than that, so i guess a mercury thermometer would have reached its freezing point. But as far as I know, mercury thermometers were hardly used anywhere by that point, since (when they break) alcohol or bimetallic strip thermometers are pretty harmless by comparison.

[@raufhafeez6895]

Interesting! One thing I didn’t understand was the repeated references to reactivity while all the simulation was geared toward was to explain the melting point. What does reactivity has to do with melting?

[@DNTMEE]

I had not idea the difference in orbital velocity between shells was so great as to have relativistic qualities and consequences. That is nothing short of amazing. I would tend to call the state of mercury as being _"Fluid"_ as opposed to Liquid. The term liquid is too close to referring to water in most people's minds. The broader term of fluid can also refer to gasses or even the flow or traffic on a road system at rush hour. In the traffic example, some hydraulic equations were found to be useful to describe the various conditions of multiple vehicle movements.

[@uesdtosignin1038]

8:57 This doesn't make sense to me. If electron become more massive as it move closer to sped of light, it should make the innermost shell larger. From the circular motion force formula F = (m*v^2)/r, if m (electron mass) is increase, F is same (more electron mass doesn't make electron have more charge) and the r must be increase. That mean the innermost shell most be larger.

[@The.Lilomay]

This explain my questions for so long when I learn about Periodic Table in high school

[@tjcihlar1]

It is an interesting phenomena. I wish there was a video version for this for people who have already taken physics and know what atoms are, there is too much time rehashing what many people already know.

[@andersbackman3977]

The inner shell electrons doesn't actually "travel at nearly have the speed of light", the electrons get closer and thus their energy increases, this leads to the effective mass of these electrons effectively increasing (from E = m C^2) and that is what does the job.

[@hexagoldprocessequipmentpl9677]

You're good at this

[@brianb9410]

Very interesting and well presented. Thank you!

[@goodmaro]

Wow, I used to teach Chemistry,, and I had no idea of the relativistic contribution to mercury's properties, thanks!

[@joy211191]

Question: But then in that case, shouldn't the elements beyond Hg, be liquid or have lower melting points and if we extrapolate this, then Cn should be a gas at room temperature? I mean this does explain the riddle of Hg, but then a whole set of new ones come into play when we solve this one.

[@X4Alpha4X]

so at what point does the relativistic effect start at? Tungsten, at # 74 has one of the HIGHEST melting temps, do those extra 6 electrons make that big a diff? or should tungsten have an even higher melting temp without relativity taking effect? also what happens to the ion forms of such heavy atoms?

[@peternyekete6802]

Great presentation.

[@AmityvilleFan]

I love you can explain everything with midlle-school level language.

[@hannahk1306]

This video gave me flashbacks to A-level chemistry! 😆 Really interesting though and relatively easy to understand.