Crystal Definition and 382 Threads

In the reaction of CV with NaOH, the order of CV is 1 (first order). However, in an experiment that I did with a colorimeter, I did not entirely come up with this value. Graphical analysis was done to determine the best wavelength from the absorption spectrum and lambda_max = 590 nm. After...

Dear all, I am now intended to do some first-principle calculations on disordered system, where VCA is an effective method. However, as to practical implementation using different methods, say Plane-Wave Pseudopotential, FPLMTO, FPLAPW, it's a litter hard to get a clear picture about how to set...

Hello all, Who can tell me the ralationship between crystal and hardness of the coatings. I do XRD and measure hardness but the some coatings with high intensity of XRD peak show the low hardness. The questions are: what direction of planes is useful for hadrness? what elements affect on...

Is it true that, if power were applied to a one meter cube of quartz crystal and the crystal were driven to the breaking point, the gravity waves produced would definetly, 100%, be orders of magnitude too weak to be detected? Apparently Albert Einstein calculated that

I was given the following question: A crystal of hydrogen atoms and a crystal of lead atoms have exactly the same crystal structure, including lattice constant. How can they be distinguished by x-ray diffraction? The solutions say that the beams diffracted off the lead crystal would be much...

The problem here is to find the maximum radius of the interstitial sphere that could just fit into the void space of cubic crystalline structures of: the simple cube body centered cubic face centered cubic My question is how is position of the void space determined in these structures?

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...

Just when I thought I understood the concept of planes and miller indices, I got stuck on a 'test your understanding' Q in my book. I can't understand that there can be two or more (110) planes in a crystal lattice? I thought there can be only one such plane. The question asks me to find the...

Dear all: Since bond energies in crystal are very important in say single crystal growth theory, and it seems very difficult to do such calculations. However, can someone give me some hints on this task, or if there is a perfect solution, please let me know. Sincerely Hongbin Zhang

in the radius ratio of a crystal, what is the difference between the radius of the interstitial atom and large atom?

Any one knows what the decomposition temperature of ZnSe semiconductor doped with Cl is? I am doing some annealing with a simple equipment but worring about the volatilization of Cl, which would be dangerous. Thanks a lot!

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

Hello, my name is Kenichi, from japan. Inorder to draw Crystal Lattice 3D Structures, what libraries for free out there to be used with C programming language ? I am still a C novice. I wonder, in chemical simulation research do you also program using C language plus some libraries to...

Well I know of the boil sugar, add then let it stick. You can form sugar crystals on the stick then eat them. Well I am about 15 years to old to be doing that. What got my interest was this picture of "home grown Monoammonium Phosphate" So I was wondering. Are there any experiments I could...

How would someone go about creating a large NaCl crystal? Is there a special evaporation technique involved with a saturated solution? As a side question why is sugar in crystal form? I mean isn't sugar a covalently bonded molecule?

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

When light passes through calcite crystal it splits into two rays, extra ordinary and an ordinary ray. Ordinary ray travels straight and extra ordinary ray is refracted. This would mean ordinary ray travels faster and e-ordinary ray travels slower because index of refraction is inversely...

My physics teacher taught me that, however, when I asked my chemistry teacher, he said NO. And now ... I'm confused. Plz anyone can help me to make me clear about this with explanation.?

hello to all here is a problem i designed myself. i don't know whether it can be solved. Question: Consider NaCl lattice of edge length 'x' m. Let Na+ carry +1 C and each Cl- carry -1 charge. Calculate Poisson's ratio of NaCl crystal. Assume no heat loss when deformation takes place...

Symmetry in crystal structures- please help! Hi there, I was hoping someone here could help explain a few things about crystal symmetry to me cos it hs me so confused (we've been doing crystals for 2 weeks and things up til now have been ok, I'm just getting myself muddled as usual!). The...

Would it be possible that Opticians will be selling to visually impaired people, Contact Lens, made from a material that has a negative index refraction, that theoretically could be altered with a Liquid Crystal "Eye-Drop" solution? Basically how far are we from a Liquid Crystal Contact Lens...

Could a crystal radio use a lead sulfide or lead selenide antenna an pick up in the infrared?

Can a crystal types radio be made to work in infrared? With an antenna of lead sulfide or lead selenide perhaps?

has anyone here ever built a crystal radio? what parts would i need and where can i get them? in the physics forum they said one could be constructed to run off the radio waves themselves, which is the kind i would like to build. thanks

Photon splitting. It's effective use in Quantum Computation? Optical Parametric Generation In the photon picture shown above, a high frequency photon (blue) enters a crystal and is split into two lower frequency photons (green and red). Conservation of energy means that the sum of...

The universe acts like a crystal [1] because the observed universe is made of huge cosmic scale atoms some seen as galaxies and galactic nuclei [2]. 1. http://www.cc.rochester.edu/College/RTC/Borge/aniso.html Indication of anisotropy in electromagnetic propagation over cosmological...

Hi, Can someone tell me how a wave is guided (in a fiber for instance) thinking in term of diffraction (or scattering) and not in term of successive reflections. And my second question is : would it be possible to "extrude" a plan diffractive element in a fiber to guide wave and have the...

Okay, I'm hoping someone here can explain this homework qustion I've got bcause we don't seem to have anything in our notes that covers it, so any help would be great- thanks! Potassium fluoride (K+F-) is an ionic crytal having density 2.48x10^3 kg/m^3 Assuming that the diameters of the K+...

I'm still a little confused about crystals and grains. Does a crystal become a grain as the metal solidifies? I'm also not clear on molecules. For instance with a body centered lattice you have nine atoms. One on each corner and one in the center of the body. So within that lattice -- what...

A NEW kind of crystal is so riddled with holes that a mere gram of the material has an internal surface area equivalent to 17 tennis courts, a record, the British science journal Nature reports today. http://www.heraldsun.news.com.au/common/story_page/0,5478,8588873%255E1702,00.html

http://www.newscientist.com/news/news.jsp?id=ns99994692 "A crystal the size of our Moon has been revealed hidden at the centre of a dying star, after an analysis of pulsations in the star's brightness. The measurement confirms indirect evidence that the cores of all such dying stars -...

For my project, I am creating a pure aluminum model with styro foam balls and toothpicks. I know this structure is a "face-centered cubic". However, I don't know the bonding angles and what kind of bonding shape (tetrahedral, octahedral ...), I need the information for the write-up. Can someone...