Leaderboard

Electrons in atoms can be thought of as standing waves corresponding to resonant frequencies, ie. a series of harmonics. In fact the shapes of atomic orbitals are spherical harmonics, akin to the modes of vibration of a rubber ball if you hit it and look at how it vibrates with a strobe light. Each electron occupies a different quantum state. It has to, as electrons are fermions. "Shells" are simply groupings of related, but different states that are possible for an electron to occupy in an atom. Each shell comprises all the states that have the same principal quantum number, n. But n is only one of 4 quantum numbers needed to specify individual possible states. They others are: - l, which denotes the angular momentum and determines which subshell the electron is in (i.e. s, p, d, f etc), - m(l), which determines which member of the sets of s, p,d, f orbitals the electron is in (e.g p(z), d(x²-y²), etc), - and finally m(s) which determines the spin orientation within that orbital. So one can have a maximum of 2 electrons per orbital, one with spin orientation "up" and the other "down". In chemistry, this accounts for the pattern of the Periodic Table of the elements, each row corresponding to the highest occupied principal shell that is occupied, 1st row n=1 2nd row n=2 etc. (cf. Aufbau Principle.)

This question has five parts and needs five answers Cut a cube of side 2 cms into eight identical pieces such that the surface area of each piece is : A. 6 sq cms B. 4 + 2✅2 sq cms C. 5 + 2✅2 sq cms D. 10 sq cms E. 6 + 2✅4.25 sq cms

Thank you for your intervention - I appreciate it +1 Can we put the trumpet stuff to one side? It's what initially got me thinking about this topic but the OP is about building the correct general mathematical framework. The rest of your analysis is correct though the introduction of temperature via the Equation of State now needs isentropic conditions to be established via Eqn 02.02, and the introduction of a variable sonic velocity calls in Newton Laplace (Eqn 00.04) so there's 7 independent equations for 7 variables . The choice of spherical coordinates certainly helps eliminate a lot of terms that might otherwise be awkward.

Gentlemen can you please give others the time to go through the 9 pages of maths posted before closing this ? I am been rather busy with other things this w/e but would comment further as follows. The NS equation or equations is a single 3D vector PDE or 3 separate scalar ODEs. That is not enough by itself to solve since it only gives 3 equations for the 5 variables involved. To solve it we require to introduce two further equations. One way is to use the continuity equation and a gas law equation of the form density = a function of pressure and temperature. This I think on first reading is Seth's method. It may be possible to reduce the number of variables by specifying spherical symmetry. But a trumpet symmetry is decidedly non symmetiric. Much of the sound energy is focused. I do believe that @MigL is a NS equation specialist and would welcome his comments as well as whatever @Mordred comes up with.

Yes I mole weighs 192g, so 192g dissolved in 1litre would be a 1 mol solution. So for 250ml you need a quarter of the amount. Not sure where your 1/2 comes in - typo? (250ml is 1/4 of a litre of course, as you correctly imply in your calculation.)

I think you can get drain cleaner which is based on strong acids (some is also based on strong alkali), but I hesitate to suggest you try, as they are fairly nasty if you spill them on you - or anything else. Citric acid has a first pKa of 3.1 whereas acetic acid has a pKa of 4.76, so citric acid is a bit stronger but not much. (For comparison a strong acid such as HCl has a pKa of -6, so in a different ballpark entirely).

If they answered you and were polite about it, I don't think you can go wrong with something like, "Thanks so much for your time, I really appreciate it."

Speculations need to be backed up by evidence. I’ve been trying to get you to show that there is some solid foundation for the idea. You claimed that “The peak of the pressure wave is hotter and the trough cooler due to compression/expansion and this does affect sonic velocity.” but this seems to not be much of an effect for normal sound levels. There’s nothing speculative about establishing this. The pressure amplitude of the sound generated is not directly from blowing, but from vibration, be it a reed or one’s lips, and trying to equate the two is erroneous. If you want to analyze the temperature effects from really loud sounds, that’s fine, but you need to acknowledge when the analysis applies and when it doesn’t. Constant speed of sound looks to be a really good approximation for most cases.

I used the term Ac a bit wrongly actually. Ac, strictly denotes the acetyl group, which is CH3CO - so I should have said Mg(OAc)₂. I'm retired and very out of practice, I'm afraid. Probably best to refer to it as Mg (CH3COO)₂ , to avoid getting into a nomenclature minefield. Regarding Zn's apparent low reactivity, acetic acid is a weak acid. At molar concentration (similar to vinegar), only about 0.4% is dissociated into H+ and acetate. If you had a molar strong acid, e.g. HCl, the reaction would be more obvious I think.

One of the best I've seen!

Hello: I am "No-One" (named Ben, the "no-one is based on the idea that in the whole of time, 100 years is nothing. We are nothing, but what we leave for the future generations.), and "I am not me (more philosophy: One ends different than when one is born, evolved through the things the person experienced). I am 52 years young, Belgian, married now 30 years with my first and only love that I met at age 23, resulting in 4 daughters and a son (in that order). Blessed with severe Asperger's and severe ADHD, my life always evolved around the logical and rational, and I live to prevent issues by fixing these before these happen. Something I am decently skilled in, meantime, having learned how to see issues coming to be. Not always successful, of course, too many variables to take into account, and the human nature: HIGHLY unpredictable. Due to my Asperger's, I am quite philosophical. Now, the general masses do not like people like me: I question everything. Including myself (I am my own worst critic), up to even my own questions. This means ... I question science as well in many a regard (which is one of the things I am quite disliked for): I found errors (and hardcore holding onto these) in science, but I can't turn anywhere with these. Brings me to my question: I have a "few" things I would like to address. Not through equations, nor Mathematica, but simple, straightforward English. Reasoning: For one: What is an equation? It's no more than an IDEA put into a scientific mathematical language, right? But what if the idea is incorrect? Example: A man falls from a building. But NOT according to Einstein: "It is the Earth falling to the man" (The Happiest Thought). Wait, WHAT? Uhm, let us please keep it to the man dropping, I mean, sure, you can state that the planet is racing to the man, if it is seen through that man's eyes, but for the rest at ground floor, it's likely not the planet speeding to the fella, but the fella to the planet, or am I wrong? Surely, I can make this into equation, but for crying out loud, to what point? I mean, to the rest of us, and especially at the other side of the planet: If it was the planet speeding up to the man, those on the side of the planet would end up soup (so to speak) from the sudden velocity acceleration while those on the other side of the planet "would fall off" due to that very same acceleration, making them in fact "weightless" (see the weightless trainings on an aircraft, same thing). But, Einstein being Einstein, he said basically: It's just relative. Or: Even relativity ... is relative. Secondly: In plain, simple English all is understood, truth is seen, and lie (read: error, red) faster discovered. Right? If I were to paste the whole law about only murder here, it would be nigh a book, that only few really understand, no? But if I were to write "Thou shalt not kill", everyone would get it? No? Thirdly: A true scientist has to keep an open mind, right? Each time DeGrassi said, that science proved God does not exist, he was being Anti-Science, or ... a quack, about this topic, abusing science to promote a bias (what i totally despise). I mean: The Empirical State of God ... is a Quantum (or Schrödinger) state: God IS, God ISN'T, and all in-between, at the very same moment. "Nought, One, and all in-between." Since God is, in science, neither proven, nor disproven. I am therefore a Religious Atheist: I equally so believe in God(s), as I absolutely do not, and all variations in-between. And no, I am factually in that mental state, about this specific topic out of many topics. I managed to teach myself to "become Quantum" (sounds silly, I know), and thus accept "both and all in-between states" of God as equally true and untrue. I do not prefer God to be, and equally so I do not prefer God NOT to be. For this is the Empirical State of God. Until we can open that box (and please let the cat be OK) and observe in which of the infinite Empirical State possibilities God is. But up to then ... He is the absolute all, absolute nothing, and whatever possible forms out there. Am I wrong? Which then brings me to the first question: "Open-Minded Science": While a friend told me, it is all very open-minded, but I think FAR outside the box. How open-minded is open-minded here? I mean, some might even seem "too idiotic to be true", even though I can substantiate what I bring. Or, if you like the question rephrased: Am i still welcome? Second question: What "is the limit" of acceptable? Note, that I am not that "scientific", but far more philosophical in approach. Hence. Kindest regards: "No-One". (Ben) If I messed up (this was the only place with "open minded" that I found, but this post might be in the wrong spot. My apologies if this is the case. Also, I do not specifically will post about (Quantum) Physics, but other fields to, if I am allowed. Thank you. "No-One". PS: I never copyright stuff. I do not mean to make any form of profit, nor is this a "throw to become famous". I care for neither, I am an absolute minimalist (safe for my PC, which is my "all": TV, Radio, Telephone, etc.). IF you see anything out of interest, feel free to use it, but within it's whole context. Thank you. N-O

No. This is not the Internet.. When you grow up with other students and continue life at a higher intellectual level, with similar to you, you forget about everything else.. ..try to talk to an ordinary person and you will have in 5 seconds, WTF?! The Internet just revealed what you didn't know..

Especially as these issues have nothing to do with other. Legally it is a bit of grey zone as many countries do not seem to have laws explicitly prohibiting marriages with animals. The wiki article is a bit of a mess https://en.wikipedia.org/wiki/Human–animal_marriage. But I think these lines of argument follow a rather similar structure. First, remove any reasonable context (there are no laws explicitly forbidding human animal marriages as these things are normally expected to happen, same as marriages with plants, rocks or bodies of water are prohibited) and then cram in something you don't like (homosexuality, transgenderism, poets). Thereby it is easy to create ridiculous scenario to attack. I mean, clearly poets are linguistic deviants who just want to disassemble clear communication. All these contortions using rhymes and unusual sentence structures rob us of our ability to clearly present facts. As such, they should be banned under law. After all, what prevents me to declare myself a science poet and force journals to publish my gibberish!

Actually nature uses rotation in some suprising ways. https://www.google.co.uk/search?hl=en-GB&source=hp&biw=&bih=&q=rotating+microbes&iflsig=AJiK0e8AAAAAY7g0_8kobF67VuYcPl8mgs7idJ3VWaj_&gbv=2&oq=rotating+microbes&gs_l=heirloom-hp.3..0i546l2.11096.32186.0.32384.19.16.1.2.2.0.176.2198.0j16.16.0....0...1ac.1.34.heirloom-hp..0.19.2308.MRvTaHdMUtY https://en.wikipedia.org/wiki/Gömböc good point +1

OK have fun. Try it with zinc too - I'm a bit surprised you saw no reaction. By the way, I should have said Mg(Ac)₂ of course.

Because the principles that govern their behavior are independent of their histories (according to SR). Don't be silly. [math]\gamma[/math] is nonlinear in the velocity.