Paramagnetism of Oxygen

Oxygen gas is condensed into liquid form and then poured between the poles of a strong magnet so we can observe its paramagnetic properties.
We send O2 gas through a copper coil, which is then immersed in about 2 liters of liquid nitrogen (77 Kelvin, or minus 196 degrees Celsius). As the O2 travels through the coil it loses enough heat to change from a gas to a liquid, and that liquid is collected in a small pre-cooled Dewar. Liquid nitrogen is poured between the poles of the permanent magnet, but since its diamagnetic properties lead to only a very weak interaction with the field, it just sloshes through as if it were water. The liquid oxygen, on the other hand, sticks between the poles of the magnet until it boils away.
Because the oxygen molecule has an electronic structure that favors the non-cancellation of two of the electron spins, its net magnetic moment is free to point in the direction of an external magnetic field (just as a compass needle does). When enough of these moments are aligned, the material as a whole behaves like a single magnet. At room temperature only a small fraction of the moments are able to line up perfectly with the external field, but when oxygen is cooled and condensed into a liquid the effect is more noticeable.
For more details on our setup see:
sciencedemonstrations.fas.harv...
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[@brainiac75]

Nice magnet and nice video. The color of oxygen is just such a beautiful blue color...

[@NickRoman]

I also liked seeing that liquid oxygen is blue.

[@sheesulhassan]

Thank you for this cool demo... I was studying Molecular Orbital theory for my tomorrow's lecture and found this video... Gonna show this video to my students thanks again

[@joeguy6351]

If you don't mind, would you explain a little of it to me, or point me in a good directions.

[@ayushrajpoot2215]

same here but i am student studying for myself

[@DeepakKumar-gd1wg]

@@joeguy6351 i don't know how much you know about this stuff so i am just going to explain in layman terms. You know that electrons spin around atoms, right? Since electrons have charge, when they spin around the atom, they create "magnetic moment" whose direction is perpendicular to the plane in which the electron is revolving. For example, if you say that the electron is spinning on your bed, then the magnetic moment will be created in the direction perpendicular to it. Now you can think of this magnetic moment like a stick. Suppose you hold a stick to some angle to which a wind is blowing. The stick aligns itself with the direction of the wind, right? Now you can think of the magnetic field between the two magnets as a wind blowing from north to south pole. Now what you will study in quantum mechanics is that the electrons have a principal quantum number called "spin" which can be either +1/2 or -1/2(this spin actually has no physical meaning. It is just a mathematical model). If an electron ha s spin +1/2 and another electron has spin -1/2 then their magnetic moments cancel out or you can say their is no stick which you can hold in the wind. But if two electrons have same spin (+1/2 or -1/2, doesn't matter) then their magnetic moments or "sticks" add up. Now what happens in o2(according to molecular orbital theory) is that all except 2 of the electrons pair up i.e. since you have 16 electrons in o2 then 7 electrons have +1/2 spin and 7 others have -1/2 spin so their magnetic moments cancel out. But the other 2 electrons have spin of same sign (+1/2 or -1/2) so their magnetic moments add up. Now when you are pouring liquid oxygen onto the magnet the magnetic moment or stick is reacting to the magnetic field(or wind). However with nitrogen gas(n2), it has 14 electrons which when arranged in the molecular orbitals give a net spin of 0 so you don't see any reaction.

[@SSHAKTHEESIVAKUMAR]

@@DeepakKumar-gd1wg Thanks a lot for the explanation!

[@acluster3411]

@@DeepakKumar-gd1wg Great explanation, well done.

[@abdulmajeed-jb8fg]

Who came here just after studying molecular orbital theory?

[@doremonrasigan3683]

From vedantu ri8?

[@lolloflashdelelbha4762]

every body

[@idrinkmilk282]

​@@lolloflashdelelbha4762with exception to you

[@backyardsounds]

That magnet has seen some stuff.

[@NatSciDemos]

Yes, we've been using it for many years.

[@johmcg64]

No it has not!

[@M4hB]

I love how Echoes Live at Pompei is in the related videos. I highly suggest anyone who hasn't seen it to watch it now.

[@namir0430]

great video... it is one of my favorite demos. Note, If you used a white background you could really show off the pretty blue color of liquid oxygen.

[@Indian-from-India]

Well done. Thanks for uploading. Beautiful & powerful magnet.

[@SmittenKitten96]

Saw a picture in my textbook and had to look it up. Really cool 🤙

[@Rayfer02]

How amazing explanation. Very instructive. Helpfull for my job. Thanks you Very much.

[@LetoZeth]

Such an interesting video, at so many levels.

[@TheEmerhh]

I had been listening to some radio station and they played dubstep while I was watching this video. It sounds awesome!

[@NatSciDemos]

@howard999999999 the LN2 is 77 Kelvin. the "--" in the description is meant as an em-dash not a minus symbol.

[@user-ih4yh9ww2u]

Such a amazing video, thanks a lot!

[@TrevorRGHolt]

Could a strong enough magnet condense the oxygen to a visible gas without cooling. Or at least bring the partial pressure of oxygen in the atmosphere higher than normal?

[@NatSciDemos]

@FTSinclair yes the induced magnetic moment is inversely proportional to the temperature.

[@EGbeatz]

after he pours on the liquid oxy and it dies down abit are we seeing the magnetic field as the gas forms that half circle ontop of the center of poles?

[@babuugamer2681]

Wow. It's amazing 😍😘😍

[@hirmizzz]

Great experiment Harvard Thank you

[@NatSciDemos]

@TehCthulhu combustion requires fuel, oxygen, and ignition, so by itself the liquid oxygen isn't flammable. on the other hand, because the oxygen is highly concentrated in liquid form, it will make any combustion happen more quickly (and violently).

[@briankerr4512]

is the o2 liquid spinning when it is between the 2 magnets ?

[@raphaelfarias8184]

Alignment of the angular magnetic moment of oxygen. Many people think that only the magnet has magnetic properties.xD Very Nice. :D Brazilians Greetings

[@waseebderang894]

This is also done because Molecular orbital leaves two unpaired electrons in each of π• orbitals Hence, electronic configuration of molecular orbital accounts admirably for paramagnetic properties

[@grandexandi]

I love these videos, but it frustrates me that they don't include any explanations at all for us who don't know anything about what's going on...

[@AndyU96]

Why does having unpaired electrons make something attracted to magnetic fields?

[@siyabongankosi9956]

lol just enjoy the video,it wont be worth it to explain MO theory if you dont do chemistry anyway

[@pompommoon3069]

Ameerhun1996 is it because it’s unbalanced?

[@heysiri4935]

kzbin.info/www/bejne/pnOQonStoMyZfLM

[@neodiy]

Can you test if gasoline is magnetic / paramagnetic or diamagnetic?

[@shuralmehki]

What would happen if the magnet were to be supercooled as well prior to pouring the liquid nitrogen and the liquid oxygen?

[@EDUC515]

What is the name of the magnet you use and where would a person go to find/purchase one? Where did you get your magnet from?

[@davionbarker1021]

What would be a way to increase the rate of liquid oxygen production?

[@apostolique1]

That's so cool! I'll have to read the description to actually understand what happened, but the effect looks so magical.

[@forerfunluckres6723]

interesant test plsease wortex coil on liguid nitrogen what electrons moved and magnetic oation pole making ! Thanks for the answer

[@joeguy6351]

So would moving super cooled, magnetic liquids create a stronger magnetic field.

[@FTSinclair]

So if that happens to liquid oxygen, what about gaseous form? Do oxygen molecules tend to gather around magnets in the same manner? Is the temperature a factor?

[@yqisq6966]

What's the strength of the magnetic field?

[@tirandoideas]

Man I love your vids

[@Petrov3434]

BRAVO !!!' • Molecular oxygen in the ground state is a bi-radical, containing two unpaired electrons in the outer shell (also known as a triplet state). • Since the two single electrons have the same spin, oxygen can only react with one electron at a time and therefore it is not very reactive with the two electrons in a chemical bond All organic compounds, including those that compose our body tissues, should react rapidly with air to form H2O, CO2, and N2 in an exothermic reaction. Fortunately for us, however, this reaction is very, very slow. • The reason for the unexpected stability of organic compounds in an oxygen atmosphere is that virtually all organic compounds, as well as H2O, CO2, and N2, have only paired electrons, • whereas oxygen has two unpaired electrons. Thus the reaction of O2 with organic compounds to give H2O, CO2, and N2 would require that at least one of the electrons on O2 change its spin during the reaction. This would require a large input of energy, an obstacle that chemists call a spin barrier. Without the quantum rules that govern the predominantly two-electron chemistry of carbon, versus the one-electron behavior of oxygen, the world that we know and love could NOT exist.

[@baywords]

can you use liquid oxygen as an electromagnetic core?

[@thedualmobius]

Just curious. At what temperature does oxygen become a solid? Follow up question. How magnetic is the solid form of oxygen?

[@NatSciDemos]

@treegraph thanks for pointing that out. better to just say that the LN2 is diamagnetic...

[@elmonoreptiliano9878]

why don't you light a match on the oxigen?

[@EngineerNick]

such good quality video thanks :)

[@joboring8397]

The vaporization rate of the liquid nitrogen increases at 0:57. Is this because condensation of atmospheric oxygen begins to occur at this point?

[@saifansari7250]

Great experiment sir ❤️❤️❤️

[@forerfunluckres6723]

Is like in wortex coil rotation pole how faster for more enrgie generated from the that rotation magnetic turbine instale extra .

[@Personnenenparle]

Schlieren imagery plz! Is oxygen gas magnetic?

[@champ121991]

Simply amazing..

[@fano72]

So cool i have seen the magnetic field!

[@redmetalicrobotdemon6409]

I read a thing about magnetitism of Carbon Nano Tubes having a current capacity of 5,000 times of regular electro magnets. I wonder if 5,000 times current and torsion capacity can move air for a flying car of some sort.

[@Murderface666]

Cool, but where can this be of use?

[@antaress8128]

I love this experiment. I'm so glad I found this channel. I watched all the uploaded videos for 1 afternoon. I studied in low budget university and we had only few experiments. Thank you so much for making these videos. This Universe never stops to amaze me. And btw why the oxygen is blue in its liquid form?

[@taoorus]

maybe cause of the copper?

[@anastasiagreem6989]

The transition responsible for the pale blue color of liquid oxygen compare to clear gaseous form is the simultaneous excitation of two molecules from triplet sigma to singlet delta. The double excitation avoids the spin forbiddeness. The energy for the transition corresponds to a wavlenght of 650 nm. Absorbing in the red means the liquid oxygen looks blue. This is only possible in the high density of the liquid so air doesn/t have this absorption with any intensity :)

[@antaress8128]

Anastasia Greem Thank you for your detailed reply! You are beautiful and smart.

[@anastasiagreem6989]

Ристу Георгиев Spasibo za compliment :)

[@TehCthulhu]

So how flammable is liquid oxygen?

[@aravindaakash6412]

Watching with earphones, so satisfying

[@TXandUK]

How does this work? I'm really interested

[@relentlessmadman]

this is a really cool experiment! were you ever a hippy?

[@juancitoperez93]

What happens if you drink liquid oxygen?

[@KishoreChandraMishra]

It is very good demonstration

[@infobiodiversity]

That was amazing ❤

[@TheresAGap]

This is so cool.

Amazing!

[@sergi044]

So what happens if your drink liquid oxygen?

[@jasonsweet228]

What does solid oxygen look like?

[@NickRoman]

So, does that help explain weather on Earth?

[@knowledgetogain379]

so satisfying 😯

[@i_am_ruhi86]

Osm 🤩🤩🤩

[@sakenandersson7315]

I don´t understnad this . Does oxygen like magnets or what?

[@ThingEngineer]

Cool magnet!

[@nihadeyvazov9162]

Thank You for this video

[@NatSciDemos]

You're welcome!

[@Speeder84XL]

Awesome!

[@waynesanders1406]

I have no idea what I just learned. But whatever it was... I learned it.

[@DanieleGiorgino]

That's pretty cool.

[@anubhavidk]

Who is here from A2 sir?(Arvind Arora)

[@prantikagautam5000]

Me

[@degavathkalavathi]

Me

[@thekidflys3471]

Way Cool! Thanks

[@lynth]

I love the key chain throw at the end.

[@Dr.Ashmita]

That pale blue color of Oxygen ❤️

[@jonathanrecer7468]

Try the conductivity of 4 state of water plz

[@daniloorbolato]

amazing!

[@XieHang]

very great and glad physics!

[@josedourado3747]

So in a strong magnetic field, with superconductivity even oxygen spins? Or it's moving because of termal expansion?

[@DeepakKumar-gd1wg]

No it is spinning because it is paramagnetic

[@SrTicoLoco]

amazing, but what I can see, only liquid oxygen is paramagnetic, oxygen gas just desperse... What about hydrogen? is liquid hydrogen paramagnetic too?

[@OPDCSV]

What can this be applied to.I think this is pretty cool!

[@h7opolo]

amazing

[@hamiel85]

@Canadiankiid93 No, your hand will be fine for a split second of exposure. This is because LN2's boiling point is extremely low and from it's stand point your hand is extremely hot. That means that for the split second your hand was in the LN2 it is actually boiling on top of your skin and evaporating. A good example of this is to pour water on a hot cooking stove, the water will almost like "dance" on the stoves' surface, then evaporate. But any longer than that and ... well, you know.

[@ecmswagger]

This makes me think of a water bridge phenomenon which forms in the presence of high voltage.

[@muditbiswas]

Daaamn Daniel

[@NickWarnerMedia]

this is nuts i love it

[@Walkingdeadman1991]

Could you breathe in pure oxygen? Why don't people use oxygen to freeze things instead of liquid nitrogen?

[@romariowilliams4907]

+Harvard Natural Sciences Lecture Demonstrations So would the behaviour of the LN2 when poured on the magnets demonstrate its diamagnetism? Cool experiment by the way!

[@johmcg64]

The liquid nitrogen cooled the oxygen gas below its boiling point creating the liquid oxygen, so cool. That liquid nitrogen has a termperature of -320.4 degrees F. The liquid oxygen has a boiling point of -297.3 degrees F so it is liquid at -297.4 and degrees and lower. This is how the oxygen gas became a liquid. Very cool! Thank you.

[@GrimKayne]

Didnt you add liquid nitrogen on before liquid oxygen? Wouldnt that have a chemical mixture meaning liquid oxygen may behave differently without first having added nitrogen

[@Extractables]

The reaction between oxygen and nitrogen only happens at high temperatures, like in a spark, lightning, or an internal combustion engine. At the temperatures of liquid oxygen and liquid nitrogen, there's practically no reaction. The liquid nitrogen boils off when it hits the pole pieces, and it cools them down. It's gone by the time we add the liquid oxygen. Often when we do this demo for a class, we repeat the sequence of adding liquid nitrogen to further cool the magnet so we don't have to make as much liquid oxygen. Thanks for the question!

[@flashhh2292]

would this happen if you haven`t cooled the magnets with the nitrogen 1`st ?

[@SerBallister]

i guess the oxygen will evaporate, violently :)

[@flashhh2292]

agreed infact after posting i was thinking and ended up to the same conclusion ... the oxigen will boil over faster so the chilling part was good call for beter video ;)

[@mariaorsic9763]

Thank you so much! This is the only way to learn.

[@waffensuperninja]

How would this experiment be relative to the lack of gravity in space?

[@ThePerfectBalls]

what would happen if i drank that oxygen?

[@JohnnyBradbury1981]

What would happen if there was a small flame introduced to the suspended liquid oxygen?

[@mairisberzins8677]

Whatever was burning that caused the flame would light up real fast even before being suspended in liquid oxygen due to concentration of it in the air just above the liquid would be far greater than 21%. When submerged, I have no idea. Could be put out due to the low temperature or... could burn even faster.

[@alejosky]

That's a big ass magnet!

[@evergreenappreciator]

@thedualmobius Obviously this is dependent on several factors, but oxygen will become solid at normal atmospheric pressure (1 atm) at temperatures below 54.36 K. To have room-temperature solid oxygen, the pressure required would be something ridiculously high. I'm not sure on the magnetic properties of solid oxygen, but I'd assume it's higher than liquid or gaseous oxygen, as there are more molecules in less space. Check out the Wiki page for more info! Hope that answers your questions!

[@gilbs8247]

what is happening?

[@funnyvideok1]

Cool

[@rajkumarsonare9574]

Wowow 😀

[@imadkali]

need some slow motion, but its amazing

[@dakotareid1566]

Wait what if u drink liquid oxygen does it turn back in to oxygen

[@odawgie6847]

William Burke depending on how much it was, I'm not sure it would kill you, but you definitely would not have a fun time.