KJW

Perhaps it would help if you read the Wikipedia article on the history of atomic theory: https://en.wikipedia.org/wiki/History_of_atomic_theory Knowing the history of atomic theory provides an understanding of how the knowledge of atoms developed over time.

Another example is a chemical synthesis, the product of a particular chemical reaction on a starting material whose structure is known by whatever means. It may be that the substance produced has never been produced before. In this case, there is no known sample with which to compare our substance produced. But the substance produced is not entirely unknown, either. It is likely to be the substance that was intended to be produced on the basis of what is known about the chemical reaction. And if it is not the substance that was intended to be produced, then it is likely to be in some way related to the starting material or the substance that was intended to be produced. In either case, it becomes much easier to analyse the spectra of the substance than if the substance is truly unknown. Proton nuclear magnetic resonance spectroscopy is especially useful in this regard.

There is a force acting on the wires due to the magnetic field. Magnetic field??? Where did THAT come from???

The solubility of Ca(OH)2 decreases with temperature. However, heat may speed up the equilibration. The solubility of CaCO3 is actually not very low (0.013 g/L @ 25 °C, although it will be lower in Na2CO3 solution), so the problem I mentioned above may not be as much of a problem as I had suggested. I think heating the mixture with stirring will eventually complete the reaction. In a laboratory setting, one could use a Soxhlet extractor to extract Ca(OH)2 into the flask containing the Na2CO3 solution, though this is probably overkill.

I think it's like eye of newt. Welcome to the alchemy forum. The problem with trying to react undissolved calcium hydroxide is that the solid particles tend to become coated with insoluble calcium carbonate, preventing further access of the calcium hydroxide to the carbonate solution.

https://en.wikipedia.org/wiki/Formose_reaction

Broadly speaking, you are asking how a chemist knows what a given substance is. In the modern day, we have several instruments that provide spectroscopic data that helps identify the structure of a substance. It should be noted that this depends on the purpose of the investigation. For example, if we simply wish to check that the substance is what it is claimed to be, then one can simply compare a spectrum of the unknown with a spectrum of a known sample. The spectrum itself need not provide much information about the structure because all one needs is that the two spectra be the same, like comparing fingerprints. By contrast, if the substance is truly unknown, then one would choose spectroscopic data that provides useful information about the structure. And different instruments provide different information about different aspects of the structure. For example, a low-resolution mass spectrum tells one the molecular mass of the substance. A high-resolution mass spectrum tells one the molecular formula of the substance. A proton nuclear magnetic resonance spectrum provides information about the environment of each hydrogen atom in the molecule, including couplings to adjacent hydrogen atoms. X-ray crystallography provides what is more or less an actual picture of the molecule, including precise bond lengths and bond angles (though this does require a good quality single crystal of the substance, and substantial computer processing of the diffraction data, and may not provide a complete picture). There is of course a lot more that could be said, but I think the above provides a glimpse into the world of the working chemist.

Unless you can produce a metric that describes what you are saying, it violates General Relativity. And unless this metric agrees with measured data, it violates reality. Although we don't currently know what dark energy is, any hypothesis needs align with General Relativity, by which I mean that it needs to use the same language as General Relativity.

As I see it, the band gap is the minimum energy difference between the bands, whereas the width of the bands themselves can increase the energy difference that is accessible. A 1 eV band gap corresponds to an infrared photon of wavelength 1240 nm, whereas a 4 eV band gap considered to be an insulator corresponds to an ultraviolet photon of wavelength 310 nm. Thus, the band gap of a semiconductor is thermally accessible, whereas the band gap of an insulator is not visibly accessible. I was unable to locate data on band widths, so I can't at present say that the energy difference between the bands admits visible photons. I'm guessing that there is an immediate absorption and lossless reemission that is due to the continuum of energy differences between the bands. This is different to refraction and different to absorption by non-metallic materials. However, I must say that the details are getting somewhat beyond me. Have you ever seen rhodamine B? It forms shiny dark green crystals and a violet solution (and violet smears in trace amounts on a white benchtop). I find this intriguing.

I don't know if thermal excitation is necessary for a metallic lustre. The energy of visible photons may be sufficient to bridge the band gap. And because of the almost continuum of energy levels, reflections would occur over a broad spectrum, appearing as an opaque metallic lustre.

It's my understanding that's how semiconductors work. It's why the conductivity of semiconductors increases with temperature instead of decreases like normal conductors.

I think enough time has passed that we can now do the problem.

He probably got it from a chemical supplier, and he knows it's silver nitrate probably because that's what it says on the label of the bottle it came in. My point is that modern day chemists do not start from scratch. They (to use a well-known quote) stand on the shoulders of giants. It should be noted that knowledge of chemistry developed over time and in parallel with knowledge of physics. I think that the scope of your questions is too large for anyone here to provide you with genuine help, as much as they may try. I recommend that you study a chemistry textbook aimed at school children. However, you may find this Wikipedia article interesting (though I haven't fully read it myself): https://en.wikipedia.org/wiki/History_of_chemistry

Ooh, don't tell the Americans that... they'll accuse you of being a communist. That's one thing I'll never understand about Americans... the way they fiercely defend their right to be exploited by the rich.

... would it be a red state or a blue state? I've also heard Trump say that Mexico should become a US state. Maybe Claudia Sheinbaum should take him up on that offer. Then Trump would have to open the border with Mexico and allow Mexicans free reign of the US. Wouldn't THAT piss off his MAGA supporters?

And that's just ONE billion dollars. For 400 billion dollars, it would take almost 12800 years. So, to accumulate 400 billion dollars in almost 12.8 years would require a THOUSAND dollars every second. Can you imagine what that would look like in coins?

This is a discussion forum, not a proofreading service.

Viruses are not sufficiently alive to be considered successful abiogenesis. One hypothesis I have seen is the RNA hypothesis, where RNA molecules act as both replication templates and catalysts, thus fulfilling the necessary requirements of life. However, it still seems like an enormous hurdle to go from that to having proteins as catalysts and therefore requiring the implementation of a genetic code.

But even if one has all the ingredients in place, there still has to be that final step where it all comes together to become a living cell. It's all well and good to be able form a primordial organic soup from simple compounds over millions of years by energetic processes such as lightning, etc., but even if all the molecules that make up life have somehow been made and are present at the same place at the same time, there is still the hurdle of it all becoming organised as a living cell.

No, as in abiogenesis, but with all the components present at the same place and time. If one had something like a bacteria "smoothie", could this self-organise into live bacteria, and has this ever been observed? I'm guessing it hasn't, but thought I'd ask anyway.

I have a question: Has life ever (re)emerged from a complete set of cellular components?

Before the ride starts, the people opposite me are at the same height above the ground as I am. During the ride, this doesn't change as the rotation axis of the ride is fixed. But due to the vector addition of the centrifugal acceleration and the earth's gravitational field, my perception of the vertical is no longer the same as the "true" vertical. The people opposite me appear to be well above me even though they remain the same height above the ground as I am. Because the centrifugal acceleration of the ride is about 3g, the perceived vertical direction is about 20° above the horizontal. Yes, all frames of reference are equally valid in general relativity.

The Equivalence Principle basically says that over distances that are sufficiently small for the tidal effect to be negligible, being in a gravitational field is indistinguishable from being in an accelerated frame of reference. This is illustrated by the following diagram: However, over larger distances, the gravitational field does differ from being in an accelerated frame of reference due to the tidal effect, which is a manifestation of spacetime curvature that is absence from being in an accelerated frame of reference in flat spacetime. What I said about perception of the vertical direction was not about skewing reality, but a consequence of the equivalence principle. I personally discovered the perception of the vertical direction when I was a teenager in an amusement park ride called the "Rotor". I noticed that the people directly opposite me before the start of the ride were very much above me during the ride. I immediately realised that what we regard as up or down is actually a perception that we don't normally notice unless we are in an environment that challenges the notion of up or down.

Note that when you are standing on the ground, you are being accelerated upward. Also, if you are in an accelerated rocket, you are being accelerated upward. And it is always upward due to perception of the vertical direction in response to acceleration by the vestibular system of the inner ear. If you are on the fifth floor of a ten-storey building, a clock on the ground floor would tick slower relative to your clock, and a clock on the tenth floor would tick faster relative to your clock. It is important to note that the clocks themselves are not actually affected, and all are ticking at the same intrinsic rate of "one second per second".

The relativistic effects of being in an accelerated frame of reference can be derived from special relativity. That is, acceleration doesn't produce relativistic effects separate from that of velocity. However, the relativistic effects of an accelerated frame of reference are nevertheless different from that of relative velocity. Specifically, clocks that are below you are slower, and clocks that are above you are faster, with the amount by which the clocks are slower or faster depending on the distance of the clock from your location in your accelerated frame of reference.