Outer space chemistry

I was told that all that is in outer space is known chemicals and gases and that there can be no other chemicals and gases anywhere. I don’t believe this, as there has to be in my eyes things we just haven’t found. What is the consensus please? Does the periodic table have room for expansion?

Not really - the whole point of the periodic table is that it represents a methodology that enabled scientists to predict the existence of elements they had not yet isolated (because there were gaps in the table). You’re 100 years too late.

There are hypothetical ‘islands of stability’ for elements beyond the top end of the table, and it’s possible to have different isotopes of existing elements - so there are some special cases still out there, but it’s not like we’re going to discover that there is a brand new metal that fits between nickel and copper.

Pretty much all possible stable elements have been discovered. The heavier you go, the more unstable the element gets. Some of the heavier elements have half lives measured in microseconds so in my view they don’t really count as an element that exists in nature. There is speculation of some stable heavier elements that have yet to be discovered/synthesized. Look up ‘island of stability’

Does the periodic table have room for expansion? Yes, at the end. There’s a bunch of artificial elements already, man-made ones. There’s ongoing work in making new ones. There are also several natural elements that were discovered based on the fact that the periodic table had “holes” in it, places where there had to be an element but it hadn’t been identified yet. But the making of new elements is generally considered Physics, not Chemistry. Chemistry is about how atoms connect to each other; what they are made of is Physics.

Is it possible that some of those superheavy elements exist in a star somewhere? Yeah. Are we expecting to find large deposits in asteroid belts? No, but because of a matter of Physics: even those superheavy elements which are expected to be “exceptionally stable” (the ones under Lead in the table) are expected to be so only by comparison with other unstable elements.

And btw: gas is a physical state… of chemicals. It’s not something other than chemicals.

The only room to expand the periodic table is in higher atomic (proton) numbers as all gaps up through 118 are filled, and all probsble isotopes identified. Higher proton number elements may exist under transient conditions but not long enough for Tony Stark to turn them into a new material for a fusion catalyst or wormhole stabilizer. It is possible that more exotic materials may exist in the extreme conditions in supermassive stars but we have no evidence to support this and they would not fit within the existing electrochemical periodic table any more than a wolverine would be at home in an aquarium.

Stranger

HEY! Yes they would fit - at the end! To the corner with the dunce cap! glares at Stranger, who definitely should know better

You asked two questions: are there unknown chemicals out there, and is there room for expansion in the periodic table. The second question has been answered comprehensively already, so I’ll answer the first.

All chemicals are just arrangements of atoms, which themselves are the elements that appear on the periodic table. We call these arrangements molecules. But while there are only just over a hundred elements, there are an unlimited number of possible molecules.

The simple ones, consisting of just a few atoms, already exist on Earth. Gases like H2 or O2, water (H2O), ethanol (C2H5OH), and so on. We can detect these same molecules in space.

But molecules can get arbitrarily large. Take a DNA strand for instance; it’s a single molecule, but with millions of atoms. You could fill the entire universe with DNA molecules and not be forced to repeat one.

So there are almost certainly chemicals out there that we don’t have on Earth. If life exists somewhere else, this is guaranteed, but even if not, it’s very likely. All it would take is a planet with an unusual combination of temperature, pressure, and elemental concentration, and you’ll probably get a bunch of chemicals that we haven’t seen before.

That said, these chemicals will still fit our current knowledge of chemistry. We know how the atoms snap together even if we haven’t yet seen every possible combination.

As has been pointed out - the OP’s question is not properly phrased - the periodic table doesn’t contain chemicals. It contains elements. Chemicals are made of elements (sometimes only one, sometimes millions.) But the question asked, even if it isn’t the question intended is interesting.

I think there is a bit of room in the middle here. Most of the chemistry we know is chemistry at STP - standard temperature and pressure. As the temperature drops there is scope for stuff we have less ability to replicate in laboratories, and similarly once we are in close to vacuum conditions the possibilities for less stable things to persist increases. That and the likely presence of much harder ionizing radiation to juice things up means that there is very likely a whole mess of interesting chemistry that we really just don’t have much experience of. Whether this usefully translates to so-far unknown compounds of real scientific interest, or chemical processes of novel and interesting types is another matter.

As Dr. Strangelove points out we have no reason to believe they won’t adhere to the rules of chemistry as we understand them (essentially applied Quantum Electro-Dynamics) but there is a lot of room for unexpected novelty none-the-less.

Would any hypothetical dark matter particles assemble in complicated ways analogous to “chemistry”?

QCD matter, strangelets, and other forms of “strange matter” that are formed of quarks what are not confined in nucleons (protons and neutrons) are not chemical elements and do not behave according to the laws of electrochemisty. If you are referring to hypothetical Period 8 eleemnts, these are only formed during supernova nucleosynthesis or spallation by extremely high energy cosmic radiation, not by any stellar nucleosynthesis processes.

Stranger

We have no way of knowing the answer to that question. There are no known forces that would enable that, but if those forces only acted on the dark matter particles, then we really wouldn’t expect to know of them.

Moderator Note

Nava, let’s refrain from insulting comments in GQ, and especially don’t glare at anyone, especially a poster who rather obviously knows much more about the subject than you do.

No warning issued, but don’t do this again.

Colibri
General Questions Moderator

She got it wrong, but I read her comment as tongue in cheek rather than insulting, replete with comic phrasing and even comic punctuation.

To the OP, science fiction and comic books have featured unknown elements found in space or on alien worlds since forever. Think of Wells’ Cavorite or Doc Smith’s Element X or Buck Rogers’ Inerton or Stan Lee’s Adamantium and Vibranium. And Superman’s radio writer turning an actual element, Krypton, into a new element Kryptonite. If not completely logical and inevitable, those new elements at least had a veneer of scientific plausibility at the time.

Today they’ve been definitively ruled out. That doesn’t mean that space couldn’t offer some surprises. Two extremely important allotropes of carbon - nanotubes and buckyballs - were found in recent decades. Other forms could still wait to be discovered. We know about carbon and the rest of the periodic table but that doesn’t mean we know everything it’s capable of.

Other planets will certainly have features impossible to find on Earth. Titan may have methane rainbows. Lots of fascinating chemistry awaits us.

[Moderating]

Not everyone read it that way. If you are going to make snarky remarks about other posters as a joke, then it’s best to make that absolutely clear so that no one takes offense. It never hurts to include a smilie. In any case, if you wish to discuss moderation the correct place for that is ATMB.

Colibri
General Questions Moderator

Standard chemistry works through interactions involving the electromagnetic force, and dark matter specifically doesn’t interact with EM, if it did it wouldn’t be dark matter. There are theories that dark matter has some kind of complex interaction like chemistry with a force that doesn’t affect regular matter, but they’re more in the ‘wild speculation’ bin than ‘we think it works this way’.

I didn’t feel her comment was snarky.

But, I do agree that including a smiley face is a good idea. Tone is difficult to interpret in written words. I smiley would remove all doubt.

A big thank you to all that responded. This has helped me look further in different directions and I appreciate that.

Actually, three allotropes of carbon: graphene is an even newer discovery.

Well, yes and no… Graphene is just a single layer of graphite.

For dark matter, probably not–it interacts so weakly with everything, including itself, that it’s hard to imagine anything resembling chemistry coming out of it. Of course we don’t really know what dark matter is yet.

More likely, though still without any real evidence, is the possibility of advanced nuclear chemistry. Within neutron stars, there are areas where the matter hasn’t been fully crushed into neutron soup, but also where atoms don’t quite exist in their normal individual state. In these places we could imagine complex interactions of nucleons with a “chemistry” that goes beyond the periodic table.

To be clear, this has almost no relation to conventional chemistry–the name is just by analogy. Still, some speculate that nuclear chemistry might serve as a complex enough substrate to even support life. Probably not, but I don’t think the idea has been completely excluded yet.