Structure Definition and 1000 Threads

What are the rules for drawing Lewis dot diagrams, besides the 1) Carbon usually has a full octet 2) Some atoms become electron deficient, others electron sufficient 3) The Duet Rule 4) Link OH if written in the formula What the "other" rules? For example, i try to draw glucose...

Hi everyone I missed some content in my lecture about atomic structure of atoms. In the lecture, the lecturer talked something about "slipping" , "easy directions" and "slip systems"...I don't really catch these stuff in this lecture. But I could find these in textbook. What makes me most...

I was wondering if anybody knew the type of steel that is used for the tube structure of steel rollercoasters and also its youngs modulus. I also need to know the youngs modulus for the polyurethane wheels they run on. I need this informattion for a new science project and have looked everywhere...

how do i draw the structure of O-iodotoluene? O-iodotoluene what does the O- stand for?

Which properties of materials depend on the crystal structure (f.c.c., b.c.c. cph etc...) of materials?

hello does anyone have any idea for the structure of boehmite? i only found that is the γ - AlOOH. any links would be really helpfull. ty. sorry for my english

internal structure <-->property?! can anyone suggest some link relating the internal structure of steel (like crystal arrangement such kind of thing) to their property like malleability, hardness etc. it's hard to get information from search engine. (it'd be better if it talks about the...

[FONT=Comic Sans MS]I need a plain & simple explanation of atomic structure. For example, if I was to consider the n = 6 shell, what would be the largest angular momentum quantum number and how many electrons can be put in this shell? Thanks for your insight!

Okay, here's the deal: I am doing an egg drop tomorrow in my physics class. We are allowed only 25 straws, and scotch tape to do it. What would be the most effective structure to use for this? By the way, my teacher didn't tell us of any limit on the amount of tape we were allowed to use.

I am confused. Doing Lewis structures is like balancing an equation, putting it together till all the valence electrons work with each other, as far as I can tell. :-p However, some atoms have A TON of valence electrons, like gold which has 25, um, how would I connect it to other elements...

To start off with, i don't know anything about quantum physics, or astronomy, but this is what i think, i think that black hole's have absolutely nothing to do with time. Blackholes, are derived from a star (duh), a very large star that had a large mass to begin with. Now in these stars that...

This question may have been asked a thousand times on here so please diredt me to the relevant post if that is the case. During a particle physics lecture I was told that although the fine structure constant is widely regarded as being 1/137 at normal lab energies, it seems to tend towards...

Just found the forum today, looks like a great community. :) Anyways, one thing I've always wondered since my university days and my Intoduction to Astronomy course... :) One thing I've always wondered is what evidence we have that a black hole is actually a singularity where its matter no...

I've been toying around with West-Point Bridge Designer and wondering how it does it's calculations. If you have a simple structure like the image below, how do you analyze the forces on each member (assume all triangles are equilangular and equilateral)? I'd imagine it's all vectors, but I'm...

Standard cosmology says that the universe is expanding, and is expanding at an accelerated rate. If the fine structure of universe is not changing, this expansion means that units of empty space are constantly being created. We know, however, that empty space is not empty, and that the...

hi this question is to do with electronic structure. What is special about the arrangement of helium, neon and argon? Please help because i really don't know! :smile:

I find in Martin Rees "Just Six Numbers" that hydrogen undergoes fusion to helium with a mass energy conversion of .007, that is, the mass of the helium formed is less than the mass of the hydrogen by this ratio. Is it a coincidence that this number is the same as the fine structure...

Admittedly I don't understand why flowers turn out to have so many different structures AND have so many species ? Is it because of the environment, and the adaptation, mutation speciation etc. In my picture folder, there are 30 different beautiful buckwheats I have downloaded, all have...

According to the big-bang model, it is assumed that when the universe was young enough (lets say z > 1100), the density fluctuations did evolve in the linear regime. Due to this fact, one can make use of simple linearized formulas such as the continuity, Poisson and Euler equations to model the...

Just for the record: \ \alpha^{-\frac{1}{2}}\ +\ \alpha^\frac{1}{2}\mu\ =\ e^{\pi^2/4} Where \alpha, the fine-structure constant = 1/137.03599911 (46) and \mu=1+\frac{\alpha}{2\pi} is Schwingers first term of the electrons magnetic moment anomaly which is a function of \alpha as...

Just for the record: \ \alpha^{-\frac{1}{2}}\ +\ \alpha^\frac{1}{2}\ \mu\ =\ e^{\pi^2/4} Where \alpha, the fine-structure constant = 1/137.03599911 (46) and \mu=1+\frac{\alpha}{2\pi} is Schwingers first term of the electrons magnetic moment anomaly. Fill in 1/137.03599911 for...

I have read yet the siticky post of Tom, so you have to be able to solve my problem anyway. :biggrin: Please see the .jpg attached below. I've got angry due to this problem. I am not able to identify the reaction forces in A and C points of this structure. The structure have two co-lineal...

What type of wave structure does a real state function correspond to? I am sorry. I meant to post this in the Quantum physics section.

*** PART I. *** THREE QUESTIONS ON "COULOMB'S LAW" The value of the constant "K" in what appears to be the "ORIGINAL" Coulomb's Law depends upon the nature of the medium. [ K = 1/4pi*epsilon ] where epsilon is the "absolute permittivity of the medium". In many modern books, I...

My professor wants the class to put some different chemical formulas in molecular structure while following the HONC Rule. He gave us six different chemical forumals to convert and I have finished five of them correctly; however, there is still one giving me trouble. Here is the given formula...

Is Boltzmann's Constant related to the Fine Structure Constant? Is Boltzmann's constant related to the Fine Structure Constant and if so how? Thanks in advance for your time and assistance.

After i say this rule the first person who says the word "race" has to go home :smile: That is not because it's a bad word, it is a very nice word with nice etymological roots and a rightful place in the human mind. It simply is not what the thread is about. ------------------ This thread...

Is defining a structure template the same as defining a structure variable? thanks.

In this month's edition of the "New Scientist" magazine (July 2004), there is an article which says that the fine structure constant alpha was smaller in the past ( alpha = e^2/ hbar c), and the speed of light was greater. Since the speed of light can be given by the ratio of E/B (electric...

Does anyone have any information about SOI. I've heard lots about it yet all i know of it, other than its benefits, is that instead of a metal on the oxide it uses a silicone. What is this silicone's structure, etc. Just some basic information about it would be great.

On http://elasticity2.tripod.com/ I have replaced all previous work with a table showing tha structural relationship between fundamental particles. (Muon and Tau will be included when I have changed the scale of current work tables). I show that there are only three fundamental particles, each...

DNA in Chromosomes: Structure unclear I am a little unclear on the structure of chromosomes and the DNA within, and thought maybe you could point me in the right direction. It's a little difficult to word this, so I hope it makes sense. This site and most other sites basically state...

The quantum of gravity is called graviton. And using symbols for quanta of length, \psi_E and \psi_B and quanta of linear momentum, \phi_E and \phi_B, the time independent structure of graviton, G^{-} is given by G^{-} = \psi_E \times \phi_E \cdot \psi_B \times \phi_B

self-similarity is a self-evident feature of structure in general- but how fundamental/deep/important is self-similarity? and how extensive/rigorous is self-similarity: are fractal structures simply a ubiquitous emergent quality of processes/form that pop up here and there- or can the Universe...

can anyone tell me what is the formula and structure of the carbonate? i am very confused about this.is it bond by covalent bond ?

Would you please give me some explanation about DNA's hairpin structure ? There is nothing mentioned about this "hairpin" term in my DNA book? Please help me, Thank you very much,

I hear about a process called DVCS ("Deeply Virtual Compton Scattering") which should allow access to new distributions of parton called "generalized" distributions. Does someone know what's new about those "GPD" ? DVCS at JLab Hall-A

If particles of energy and matter can be described as spherical standing waves, vibrations emerging out of of the vacuum itself, the equivalence of inertial mass and gravitational mass could be easily explained? (<-(<-(P)->)->) and (->(->(P)<-)<-) becomes (<-(->(P)<-)->) A particle is...

Please, help me to calculate the band structure of Si using the pseudopotential method. I will appreciate if you send me a simple program of calculation in any programming language very much and will be very grateful for any link or reference. The problem is than I've read the pile of books and...

I'm putting this question here because I can't get any help from the HW forum (It's actually not a HW, but it looks a lot like a HW, so I won't be surprised if it gets moved there). Source: Anderson, Principles of Relativity Physics p. 13, prob. 1.4 "Reparametrize the rotation...

Structure Validation ... What are the softwares/procedure used to validate the PDB Structure obtained from various softwares like Swiss Model ??

I am overwhelmed by this HW problem I have. Coming back from spring break, our professor blasted through the entire chapter covering analysis of structures, and then assigned this problem for HW (see attached). I am completely stuck. I basically don't know if I am on the right track. I...

This paper : Hyperbolic Universes with a Horned Topology and the CMB Anisotropy http://arxiv.org/astro-ph/0403597 ...press release: http://www.newscientist.com/news/news.jsp?id=ns99994879 proposes a universe with the shape of a horn. This is a hyperbolic space with negative...

Source: Anderson, Principles of Relativity Physics p. 13, prob. 1.4 "Reparametrize the rotation group by taking, as new infinitesimal parameters, ε1 = ε23, ε2 = ε31, and ε3 = ε12 and calculate the structure constants for these parameters." My assumptions: (1) The εij mentioned in...

I want a list of Proteins of Unknown structure... Where shall i find it ?

What are the approximate relative sizes of the following energies? a) The n = 1 to n = 2 energy difference in hydrogen and the rest mass mc^2 of an electron b) The n = 1 to n = 2 energy difference in hydrogen and a typical fine structure splitting in hydrogen c) A typical fine...

Which are good databases to find 2D structures of molecules like the following: http://www.accelrys.com/cases/images/melanin2.jpg It is supposed to be a form of melanin, but I need a better one :) Swissprot won't work, since it is not a protein.. couldn't find anything in Entrez either :(

http://arxiv.org/PS_cache/astro-ph/pdf/0401/0401094.pdf a 24 page paper on the "FINE STRUCTURE", concludes that it is invariant over cosmological time scales.

Experiments to describe the band structure of bulk (solid) materials? I just want to know the name of some of the most used techniques to describe or obtain information of how the band structure of the material is. Not by theorethical calculations, just experiments. For example, let say I...

PRESS RELEASE UCLA Team Maps How Genes Affect Brain Structure, Intelligence UCLA brain mapping researchers have created the first images to show how an individual's genes influence their brain structure and intelligence. Complete text at...