Structure Definition and 1000 Threads

I realize this is related to biology, but I think the question would be better suited to those who study or have studied physics. The question is this: I learned recently that the cavity in bones, actually increases the overall strength of the bone, even though it has less mass than if it were...

Well, we know how quartz and glass are a network SiO2 molecules *But what if we replace the Si atoms with carbon? In other words, what if we have the same network arrangement of CO2 molecules? -Is there a name for this network solid? Edit: Perhaps I am referring to "CO2-V", possibly?

this is my first post on this site but it looks like the sort of ppl that i would like to associate myself with. Unfourtanately, I have not had any formal schooling for any mathematics above calculus but i have read a few books and papers and am trying to make due. I was studying about the...

i am attempting to figure out the lewis structure/ bonding scheme for CH3NCO. so far i have: O=C=C-N-H l l H H the Hs are attached to the second C then the N the formal charges seem to be ok i have a formal charge of 0 for O...

for a ferromagnetic metal, the there will be splitting of energy band(one for spin up e- and one for spin down e-) under the influence of external magnetic field. the it is known as exchange splitting. here are my questions 1. what determine the degree of splitting? i guess it depends on the...

I got another problem with my Chemistry Homework. I need to put the Electron Dot Structure for the following. 1) Lead Oxide 2) Potassium Sulphide 3) Sodium Nitride 4) Silver Oxide 5) Copper Chloride 6) Calcium Chloride Hope somone can help

What is the structure of the liquids??isn't there any way by which we can differentiate between structure of liquids...And above all what is that "thing" present between individual atoms in liquid state? All these questions arose while studying phase diagrams...because we had FCC,BCC(etc.) for...

Hey, I have some homework questions and I'd appreciate some clarification. As a class we did an experiment where we put egg white into seven different test tubes, and then introduced seven different solutions, one to each test tube. The different solutions were weak & strong salt solutions...

Hi, I have the following problem : I generate GaAs (zinc blende structure) supercells, and then I want to replace some As atoms by N atoms. Let's say I have fcc conventional cell repeated twice in the x, y and z direction so that I have a total of 64 atoms, 32 of Ga and 32 of As. 8 atoms...

i need to know about Glass Structure, Propertie for a coursework. and also some information on other type of glass...E.g. tempered, bullet proof..ETC thank you for helping

Please can you help me and provide information on this topic: ***Glass' Structure, Propertie ** this is for my [SIZE="2"]As physics studies thank you

The attachment shows a structure. I'm supposed to calculate the forces in the members B and C. I try the following: \sum M _A = BL + 2CL - F \cdot {3 \over 2}L = 0 \sum {F_Y = B + C - F = 0} Solving for B and C from this doesn't yield the correct answer, which is B=3F/10 and...

Hi I have the following problem: To calculate the fine structure energy corrections for the hydrogen atom, one has to calculate the expectation value for (R,R/r^m), where R is the solution of the radial part of the schroedinger equation (i.e. essentially associated laguerre polynomial) and...

structure of the lunar crust and the "thumper experiment" Hey guys, I know that this is an Earth's forums but I have a question about the moon. On Apollo 14, an experiment was done to determine the structure of the lunar crust down to a certain depth. This was done by detonating explosives...

Even Einstein said that it was important to be able to visualize concepts. Words are important tools we use to visualize concepts. Aren't present words used in relativity like warped, bending, fabric, and sheet confusing? These are words we generally use to depict 2 dimensional concepts...

What makes truss bridges so strong? Like if you have something supported by triangles, why is it good? I don't really understand the physics behind it.

[Q0]An old neuropsych prof of mine told me that any biological neuron layer A that feeds into another layer B will mostlikely receive feedback. Now is this feedback: [I] Direct, meaning that some axons from B will return to A o [II] Indirect, B to C...D to A (cyclic) I know II occurs...

23rd Solvay Conference is 1-3 December 2005 in Brussels and the official title is The Quantum Structure of Space and Time The unofficial theme could be "Look who didn't get invited!". Who might have something new to say about the emergence of 4D spacetime? (Loll maybe? Nope, not there. :smile...

For Zn = { 0, 1 ,...,n-1}, the algebraic structure (Zn, +, . ) is a "ring", i.e., it has nearly all of the usual properties of addition and multiplication that we use unconsciously most of the time(where the opertaions are defined by performing them in Z and then recording the remainder on...

Hello, I am not sure this thread should be here, but I will ask anyways. The structure of chorphyll A and B differ by 4 atoms attached towards the head of the molocuel, which I believe is 3 hydrogean and a carbon for B( correct me if I am wrong) and just a hydrogean for A. There is a carbon ring...

If found a few places that suggest that CO2 1 has a face center cubic with 4 CO2 atoms in the unit cell. Does this sound right? I could also use some literature source that backs this up.

Could you check these? Which one of the following ions or molecules can act as a base? H2S NH4 ALH3 CH3 NH2 I chose H2S. Is this correct? Also I had to weire a resonable lewis structure for the molecule that has the following skeletal structure: O2NONO2 I wrote...

Hi! to everyone on the forum. I am new and did not really know where i should of posted this thread its not homework its just a question i have. A friend of mine asked me a question about a book he read about (atomic spectra and atomic structure by Gerhard Herzberg). Gerhard Herzberg said...

This is the question: http://www.maths.tcd.ie/~cockburd/Question.jpg It's not a homework question, merely one from a previous years tutorial sheet. Okay so it's tetragonal conventional unit cell, has a sort of face centered structure right? Em.. so that would mean it has a four point basis...

I recently made a post here asking questions that where clearly rediculous. I guess I need to be more obtuse. The reason I asked it here is that I'm looking for any possible way in which the 'tornado-like' rotation of galaxies could be explained by any kind of possible atomic structure in 3D...

in case of interest this got published in the journal Science, in July, and just now became freely available online. http://www.arxiv.org/abs/astro-ph/0510197 Mapping the Large Scale Structure of the Universe David H. Weinberg 4 pages, 1 figure. A brief, semi-popular review of large...

okay here's the equation: In a certain molecular structure, the total energy E between two ions is given by E= (-5.6/r) + 10e^(-r/3) where r is the distance seperating the nuclei. now i already sketched the graph but i don't know how to find the domain of E, or...

can anyone proove the following "IN A LOADED STRUCTURE THE POTENTIAL ENERGY OF THE SYSTEM IS MINIMUM IN ITS EQUILIBRIUM STATE"

Consider a nucleus with N neutrons and Z protons. Can one justify it alternatively as a nucleus with N + Z protons and N electrons, the latter occupying orbitals either confined to the nucleus or following beta decay according to their electronic potential?

Hi, Can you please suggest me a very good book on Data Strucuture and Algorithms..I already have Cormen,but i am looking for more impressive book .

Does anyone know a good website that gives info on drawing the structure of organinc molecules? Or can anyone teach me?

Hello, I just registered to these forums but already visited this place for a while. I have a question that fits this particular subforum (I hope). It is related to another hobby of mine, which is knife collecting/making. Let me give you first some background info on the subject, in order to...

Dear all: I've been tortrued by this problem for a long time, please help me as possible as you can. 1. I want to know, after one get a dispersion picture of E(k), how to judge one of those curves stems from, say, px/py/pz sigma/pi (bond?)? That is to say, how to judge the curve's...

What are some of your favorite nanotechnological applications of cell or virus structure and function?

PCCP Hot paper: Theoretical breakthrough - analysis of the errors in explicitly correlated electronic structure theory

Why does the secondary/ tertiary structure of a protein exist? Is it due to the fact that all the bonds in polypeptide are not straight as we tend to draw them? ie - bond angle, such as the 109.5 degrees for C-C, exist and also bonds are free to rotate unless hydrogen bonds are present. (as they...

Just a quick one guys. I have been revising and I have come across a question that I thought I knew the answer to. Q. There are many isomers of C16H34. What features of the structure of an isomer would cause it to auto-ignite easily? I thought that isomers with 'branches' (e.g. methyl-...

I have my doubt,solution and question in the attachment that followed.Thanks for anybody that spend some time on this question.

Hey all Why does Silicon Dioxide have a Giant molecular structure, while Carbon dioxide is made of simple molecules? They both have 4 electrons on their valence shells, so why wouldn't Silicon Dioxide be a simple linear molecule? (gaseous).

from the Alchemist Newsletter from Chemweb.com Full story at Living metals by the European Synchrotron Radiation Facility (ESRF).

Hi all,, I want to learn the course Data Structure and algorithms.Can u pls all adivice good books and strategy to succumb to this course well. I need urs suggestions badly as i don't have any much background in computers.. Pls help

There are many different types of kidney stones, but the most common is calcium oxalate, CaC2O4. The pH range of blood is 7.2-7.3. The pH of urine ranges from 4 to 8. Draw the Lewis structure of oxalic acid (H2C2O4) and the oxalate anion (C2O4-2). H2C2O4 Ka1 = 5.6×10-2, Ka2=5.42×10-5...

Three rods with length l and mass m are arranged like the figure in the attached file. There connections are without friction. One rod is horizontal and the other two parallell and in the same plane. An elastic string connects point A and B. The tension in the string is proportional to its...

3. Which of the following is the molecular shape of the ion, ICl4-? A. Tetrahedral B. See saw C. Square planar D. Square pyramidal E. Trigonal pyramidal I drew the lewis structure, 4 chlorines bound to an Iodine. Iodine has 7, Each clorine has 7 with 35 total, the bonds...

i still don't understand why when the 3d sublevel is half-filled or completely filled we get : 3d5 4s1 or 3d10 4s1.. I need a real expert to clarify it for me.. Please its urgent. Thanks Joe

Did we still have a big bang?

I want to do a Drop Test Analysis of my structure(Honeycomb like a box) from a height of 20ft...with free fall gravity...can i simulate this analysis in Ansys...will i have to purchase some specific module of this analysis in ansys...what is ASTM standard for this particular test?

Dear friends, I'm a 2nd year physics student and I've taken a subject called "Introduction to the structure of matter". It's a short of introduction to quantum mechanics(blackbody radiation, Schrödinger's equation, statistical mechanics etc,) I would like to ask you what textbook you...

I'm asked to draw 5 possible lewis dot structures for this ion. But I can only think of one. which I 've attached here. I'm supposed to draw them and determine which is the most favorable. I know I can do that by calculating hte formal charges, but first I need to draw these structures. Any...

Is 2,4-Pentanedione a ring structure or just a hydrocarbon chain with double-bonded O's on C 2 and 4? When showing the reaction with the Iodoform test what would the chemical equation be? I know it is 2,4-Pentanedione NaOH --> I know how this would work with a single...