exchemist

But this is exactly the language I find confusing. Binding implies achieving a lower energy state, so that work has to be done to free the bound entities from what binds them. Whereas what we seem to have here is a higher energy state than the quarks would theoretically have if it were possible to observe them separated (and at rest). But I'm getting a sense from you and @swansont that the term "binding energy" is best avoided in this context. The mechanisms are clearly quite different, probably related to this asymptotic freedom idea that I have not fully got my head around.

Not at all. The dipole is due to a distribution of electron density that is offset, to some extent, from the +ve charges of the atomic nuclei. The internal structure of the nuclei has no bearing at all on this. The dimensions of atomic nuclei are far too small compared to the dimensions of the cloud of electrons. A molecule like H-Cl has a dipole because the electrons in the bond between the atoms are biased more towards the Cl atom than the H atom, giving the H atom a partial +ve charge and the Cl atom a partial -ve charge. That effect arises due to the way the electrons occupy successive quantum mechanical states, starting with those of lowest energy. Elements on the right of the p-block of the Periodic Table have valence orbitals that experience a strong nuclear charge in relation to their average distance from the nucleus, whereas those in the succeeding s-block are in the next quantum shell out, so they are not attracted as strongly by the nucleus. It is all to do with the quantum states available to the electrons.

OK. Thanks. So one can't pull quarks apart by doing work against the binding interaction. I can also understand that the (theoretical) masses of the quarks themselves in the model may be small compared to the total mass of the proton, if the quarks also have a great deal of potential and/or kinetic energy. But I'm struggling with the way some articles , e.g. Wiki, speak of QCD binding energy as if this is a source of extra energy, whereas in the case of nucleons in the nucleus - or electrons in an atom - the binding energy is the amount by which the energy is reduced as a result of the extra stability conferred by the binding attraction. It would seem that the term "binding energy" is being used in the opposite sense to that in which it used in these other contexts. Can this be right, or have I misunderstood?

The anions move to the anode, which from the point of view of the electrolyte, has a positive charge, not a negative one, But as the anions are discharged at the anode, it means the anode becomes the source of the electrons that flow in the circuit, round to the cathode. So from the point of view of the circuit, the anode is the negative terminal of the battery. The two points of view are opposite because in the electrolyte the electrons are moving in the direction preferred by the chemistry of the cell, while in the circuit, they flow back to where they started.

As a chemist, I am struggling with this. In, say, a helium nucleus, the rest mass is less than the rest mass of the "free" neutrons and protons from which it is made - the so-called mass defect. That makes perfect sense to me because, to separate the nucleus into its components, you have to do work against the strong nuclear interaction that holds the nucleons together, i.e. an energy input is required, which of course is then reflected in a greater rest mass of the separated nucleons. And hence the converse occurs during fusion, leading to a net output of energy when the nucleons combine and become bound. But when it comes to the quarks that form a proton, say, the opposite seems to apply. The proton has far more mass than combined mass of the three quarks that make it up are said to have in their "free" state. So apparently the bound quarks are in a higher energy state than free ones. This suggests a proton is thermodynamically unstable with respect to the free constituents - and should spontaneously fly apart, if whatever kinetic barrier there is to it doing so could be overcome. Can someone with a bit of nuclear physics explains to me how this works? I have not found an internet source that tackles this squarely - or not to my satisfaction.

In a high energy collision, the original particles may be annihilated and both some new ones and some radiation may be created by the interaction. Energy, electric charge, linear momentum and angular momentum will be conserved. Objects, i.e. bits of matter, don't obey conservation laws, fairly obviously*. Some of their properties do. But you have not answered my question. Why did you choose to quote that obscure and incompetently written link as a source, when there are so many competently written ones available on the internet? * If I crash my car into another one, I may end up with 2 crumpled cars, 2 hub caps, a headlight, a wing mirror and some fragments of windscreen. So the number of objects is not conserved, but some properties (energy, momentum) will be.

And you have been asked to do this for a school project? Really? What have you been studying in school recently that relates to this?

Einstein said nothing of the kind. Let's go through it. I quote the text of the link below: When Albert Einstein posits that energy and matter are one and the same, and one can be converted into the other, most people could not wrap their heads around the idea. They can imagine burning a piece of wood (matter) to get heat and light (energy), but the workings of chemical reactions (in this case oxidization) is well-established. But the idea that the stuff of matter itself (neutrons, electrons, protons) is made of this ethereal, barely-understood thing called energy, flies in the face of conventional wisdom and reasoning. We've come a long way since then... - Einstein never posited that energy and matter are one and the same. What E=mc² says is that mass is associated with energy and vice versa. Not matter, mass. Note that mass is another property of matter, just as energy is. Confusing mass with matter is a similar category mistake to the one you have been making. - And he did not say that they are the same, as quite clearly they are not, having completely different units. There is an "equivalence" between the two: when you multiply mass by the square of the speed of light, you find the associated energy. - It is rubbish to say one is "converted into" the other and Einstein never suggested that. Both are present together. When you charge a battery its mass increases, although not enough to measure. That is what E=mc² means: the chemical potential energy added to the battery when you charge it increases its mass. Just as the mass of an atomic nucleus depends on the potential energy of its constituent sub-particles, as revealed in the "mass defect" when you split a heavy nucleus into two parts in fission. - The fundamental particles of matter are not "made of energy". They have energy. Whoever wrote that passage on the website is incompetent. Why did you use it, when there are competently written sources all over the internet?

What that link states is garbage.

If you can't respect the meaning of established terms, you are not going to get very far. Here is a definition of energy: https://physics.info/energy/ A property of a system. It is thus meaningless to speak of the property as if it were able to exist on its own. That would be like trying to talk about a bottle of momentum, or a jug of the colour blue.

Terms in physics have quite precise meanings. Energy is one such term. If you decide you want to ignore the meaning of that term, you will not be able to talk to anybody about your ideas, because nobody will be able to understand what you mean. This article explains what a category mistake is: https://en.wikipedia.org/wiki/Category_mistake If you think energy is "stuff" you are making a category mistake, confusing a property of entities with an entity. It's like thinking you can have a jug of blue, or a bottle of angular momentum. Both are nonsensical.

No that's wrong. You have fallen into the "Star Trek trap". Energy is a property, an attribute not an entity. You are making a category mistake. This will lead you into nonsense if you are not careful. I fear it is already doing so. It is nonsense to talk of energy having a shape. A physical system that has energy may also have a shape. That is different. A physical system may consist of particles and/or fields. Those are the entities that physically exist. They can have energy as one of their properties. But if you start talking about energy on its own, as if it has some kind of independent existence, you are not doing science any more but talking nonsense. It's like talking about the shape of the colour blue.

Just be careful not to equate energy with some kind of substance. You can't have a jug of energy. "Pure energy" is Star Trek, not science. There's always a system, whether it is a particle of matter or a system of fields of some kind, like radiation. The same goes for electric charge. That too is a property of a system. It makes no sense to say that when charges cancel you are left with "nothing". What you are left with is an uncharged system of some sort. That is not nothing.

Steady on. Particles are not "made of" energy. Both mass and energy are properties of physical systems. Particles have energy and mass, but they are not made of them, any more than they are made of spin, momentum or electric charge. You can say mass is energy at rest, if you like, but you have always to be aware that these are just properties of some system. Particles do not annihilate into energy. They annihilate into radiation - which has energy, along with other properties (frequency, amplitude, angular momentum....).

Hmm. I'm not a mineralogist but the angles between the crystal faces in your pictures look to me as if they could be marcasite. Marcasite is an alternative crystal structure of the same chemical compound - FeS2 - as pyrite. Here is a picture, in which you can see the angles between crystal faces: https://www.crystalclassics.co.uk/product/marcasite-15660/ The acute angle, < 45 deg, is quite different from pyrite, which generally has a cubic or icosahedral habit, i.e. with angles >/= 90%. But maybe someone with more knowledge of minerals can comment. @sethoflagos, perhaps?

Very pretty pictures.

This seems a very tricky project for school homework. There are various functional groups in the molecule that could perhaps be exploited, but a lot would depend on what else might be present. What have you been studying recently that might shed light on how to tackle this, or provide more context?

How about thinking about city dwellers? Suppose you are in a terraced house or an apartment. How would you see that all working?

The role played by atomic nuclei in chemical bonding and intermolecular attractions is to provide the potential wells that confine the electrons in their orbitals. The variety of forms of attraction between atoms arises from the ways in which the electrons in adjoining atoms behave. The "Moon model", put forward in the 1980s by Robert J Moon and apparently not taken seriously today, concerns nuclear structure. This has no impact at all on chemical bonding.

This is all about the behaviour of electrons in atoms and molecules, not the nuclei. Hydrogen bonding remains I think something of an enigma. At one time there was a view that it was just a special case of an attraction between permanent dipoles, but in fact it has directional character, which seems to involve the electrons of the "lone pairs" of electrons on the electronegative atom. So there seems to be an element of electron pair sharing, as in a covalent bond.

Permanant dipoles are easy to explain. You have a molecule with partial +ve charge in one place and a partial -ve charge somewhere else. The partial +ve charge will attract a partial -ve charge in a neighbouring molecule and vice versa. So it's just like the attraction between oppositely charged ions but involving only partial charges. London forces, also known as dispersion forces, arise due to "flickering, fleeting dipoles" due to motion of the electrons in an atom or molecule, which induce dipoles in the neighbouring ones. The strength of dispersion forces is greater between atoms (or molecules involving them) that have greater polarisability, which tends to mean larger atoms with a more diffuse outermost shell of electrons. As I recall, the random fluctuations in electron density that give rise to this arise from the same quantum mechanical principle responsible for vacuum fluctuations - basically another manifestation of the uncertainty principle. The name Van der Waals forces is given to all intermolecular attractions that don't involve a chemical bond. So the term includes both London (dispersion) forces and the attraction between permanent dipoles. (But it would not include hydrogen bonds, as these have some directional bonding character and are thus not entirely electrostatic dipole attractions.)

The idea of an "energy particle" doesn't really make much sense. Particles have energy. They can't be energy.

The blue flame sounds to me like sulphur burning. I think if you heat pyrite (FeS2) you will drive off sulphur and form FeS and then in the presence of air probably you will get iron oxides. If you add HCl you will get chlorides, which can look pale green. I suspect your first picture, after addition of acid, could be a mixture of oxides and/or hydroxides of iron plus chlorides, hence the red/brown and greenish crystals. The later pictures seem to show crystal growth - rather nice dendritic growth in some of the pics. Would that make sense of what you saw?

Not that it matters, but nobody has mentioned CaO2 apart from you. My post referred to CaO. OK but I was quoting that reaction to make my point that there does not have to be evolution of hydrogen, as you were previously suggesting. Regarding the separate issue of thermal stability of these hydrated minerals, you will know better than I. However the link that @joigus provided speaks of water retention at depths of up to 200km. That seems to be what they mean by "deep" in the context of water recycling in tectonic processes. So evidently they think serpentine-type minerals can survive for a while at such depths - if the subducted slab is descending fast enough (which seems to be the key variable their paper is all about). They seem to associate "deep" retention of water with water retained beyond the island arc, i.e. not entirely returned to the surface via island arc volcanism. When you say 600C, what pressure are you assuming? As the thermal decomposition involves release of water, the equilibrium will lie further in favour of the hydrated mineral under high pressure.

We would an accompanying description: a picture on its own wouldn't tell us much. What acid(s) did you react it with?