Metals Definition and 340 Threads

Hi, I am trying to understand the reflectivity from metal surfaces, but I'm stuck... I am finding contradicting results and I can't figure out where I'm going wrong. I am reading a paper [1] about IRAS (Infrared reflection absorption spetroscopy) where an IR beam is reflected from a metal with...

So far we've learned that ionic bonding is between metals and non metals, now we are learning about covalent bonding, so far it seems that covalent bonding is only between non metals. Is this true?

Hi everyone, I'm working on random materials which are coincidencely oxides and showing semiconductor behaviour... Some of these are metals and i suddenly realize MOS (which are practically everywhere). I know them, i know how they work and behave still i can't get to understand the effect of...

Homework Statement You use a steel measuring tape and measure the length of an aluminum bar. You measure a length of 20.700 m when the temperature is 21.2 degrees C. What is the measured length when the temperature is 29.4 degrees C? Homework Equations L = L0(1+\alpha\DeltaT...

Hello everyone! I would like to know if there exists any metals with a relatively low temperature at which polymorphous takes place (say lower than 400C). Also, would the metals revert back to their previous crystalline structure if cooled down in a short period of time? Thank you very much!

I know about the typical case of Paladium, which is said to "absorb 900x its volume in hydrogen". But this is completely vague. I'd like to know more about the theory of absorption as well as of other materials, like Nickel, Niobium and other transitional metals. Would someone, please, give me...

Homework Statement A plane wave is passing through a metal. Show that the impedance Z can be given by Z = \sqrt{ \frac{2 \omega \epsilon _0} {\sigma} } \frac{Z_0}{1-i} where Zo is the impedance of free space and sigma is the conductivity. You may assume that E is polarised in the x...

Hi all, I'm just wondering why pure metals, whatever kinds, do not have Raman peaks. Because the visible light cannot penetrate the metals? If so, what kind of EM wave can penetrate metals? Just need some key words for further information. Of course, I would appreciate if you would explain...

Hello, I'm studying about superconductivity. So far I understand that the material needs have zero resistance and meissner effect to be a superconductor. But why materials such as copper or gold are not superconductors? I think it's something to do with some quantum effect like cooper...

I did an experiment in which I used an anion exchange resin to separate nickel from cobalt but I don't understand the theory behind it. What I know is that the ion exchange resin uses quaternary ammonium groups as its cations but that's about it. First we packed a column with the resin then...

I know that dielectrics polarize light reflected at/near the Brewster angle, but why is it that metals never do this, only dielectrics? Also, does anyone know of a good, simple conceptual explanation for why light becomes polarized when it's reflected from dielectrics?

I am very confused at why some metals can be miscible mixed while some are separated during solidification. Can someone help me on this? Great thanks.

For example cobalt, rhodium and iridium. I know that Co(II) and the Co(III) ions have a coordination number of 6 and that Co(II) is more common because cobalt is usually more stable in the 2+ oxidation state but when it coordinates NH3 ligands the 3+ oxidation state becomes more stable. Is this...

Like, maybe transmutate certain elements into rare metals that we have a very limited supply of? By "all of the Sun's" energy, I mean an amount of energy similar to the amount we could collect from solar panels if we covered the Earth with solar panels (obviously that isn't feasible, but we...

Hey someone please explain why some metals have 0 resistance at 0 kelvin (absolute zero). Please explain the complete mechanism properly.

Hello Forum, Does anyone know where I can find the slater bases for the alkali metal 'np' orbitals and the noble gas '(n+1)p' orbitals, either altogether or individually? I'm a physicist and wanted to know what the standard (or even non-standard) reference is? I know that the...

Homework Statement A cylinder of radius r is surrounded by a concentric cylinder of inner radius Ra and outer radius Rb. The inner cylinder has a charge density lambda (charge per unit length) and the concentric cylinder has no net charge. I have to find the electric fields: a)inside the...

Homework Statement This is more of a concept that I am confused on. IF there are 2 metals, one on top of the other, and they are attached to each other and attached to a wall, and the only thing different between the two metals is the thermal expansion. When heated will the metal curve...

Fairly straightforward question: Why are nanoparticles generally made using metal, that too generally using gold, silver etc?

As is commonly known metals are good mirrors i.e. they reflect very well visible light. I wonder whetehr is it true for frequency much higher then the frequancy of visible light. Does exists the frequency for which metals are almost transparent?

Why do Fe-C and other metals exhibit upper and lower yield points? And also can you get substitutional solid solution in any Fe-C metals, like ferrite, austenite etc?

[b]1. When reacting metals with water, under what conditions do you get hydroxide and under what conditions do you get oxide? [b]3. is it all reactive metals like Na and K form hydroxides and non-reactive ones form oxides? Can anyone tell me the details of the reasons for such difference?

for metals the conduction and valence bands overlap. So how do you distinguish between the conduction and valence bands? How do you find out the lower limit of the conduction band and the higher limit of the valence band? Or is it the case that the highest conduction band in a metal goes from...

In a 1964 publication Bruno Rossi describes an experiment where cosmic rays could penetrate dense materials. Finding that cosmic radiation at sea level could penetrate over 1m of lead. In these same experiments he was also surprised to record a higher rate of detection, as many as 35 per hour as...

Could someone please explain to me the idea of M state metals, or Mon-atomic metals, I've heard that they were High Spin superconductors and that when heated they loose weight, so much so that the scale they are placed on reads negative. So, my questions are: How is this possible, and Why on...

Hello, I'm trying to find a metal that has a conductivity that's about 150% that of stainless steel grade 384. I've been looking for some charts that compare conductivities of metals but all the charts I find seem to have a few discrepancies. Could someone give me a link to a reliable chart...

how many metals can amalgam on mercury ?

hey guys, I've been given an assignment on the topic of eddy currents and magnetic induction. We have been given info that when a magnet slides down an incline over a magnetic sheet, the eddy currents in the metal acts as a braking mechanism (lenz's law). I've done some research and what i...

Why is alchemy not real? Did anyone ever figure out how to change base metals into gold? What is the closest anyone has ever come to this? Assuming they haven't , why can't they do it?

Ok so my question is as follows: Can Maxwell Boltzmann statistics be used to describe electrons in a metal at room temperature? I know that the Fermi Temperature in metals is about 10^4 K or something rather high, so does that mean that the metal / electron gas would need to be at a...

Homework Statement I'm struggling to understand the relationship between the Debye temperature and the speed of sound in a substance. An example problem given is: Estimate the Debye Temperature of Silicon and Lead, given that their respective speeds of sound are 9150 m/s and 1320 m/s. (not...

Homework Statement I'm given two identical pieces of metal (in size, shape, color, density, etc.) and no other materials to work with besides my hands. Using only those two pieces of metal and my fingers, I am tasked with determining which of the two pieces is a permanent magnet (the other is...

If one were to take a powerful source of electricity, such as a bank of high-voltage electrolytic capacitors, and short the source across a thin length of metal wire, the wire would "vaporize." My question, is what is actually happening to this wire? If it were a very thin strand of aluminum...

What are the dielectric constants of metals and i have heard that some materials have dielectric constants that are complex numbers. Please tell me which materials have complex Dielectric constants?

Hi, It is seen that noble metals (gold, silver) show a negative permittivity in optical frequencies. Can somebody explain the physical interpretation of this phenomena? How is the negative permittivity measured? Really appreciate if someone could point me in the correct direction. Thanks.

Why is standard reduction potential of beryllium and magnesium lower as compared to heavier members of the group while the reverse is true for alkali group? I read somewhere that this is due to more negative hydration enthalpies of these metals but shouldn't it make oxidation of these metals...

Placing a block of metal in a solution of its ions causes it to go into some kind of dynamic equilibrium such that the metal ions form from atoms and atoms from ions at the same rate. In the first place why does this phenomena occur? Is it something that can be described using Physics...

A 2 gram Magnesium (Mg) ribbon is burnt in air . The burnt ribbon is collected and weighed. Would it be greater than 2 grams or lesser?

I have a question regarding the possible oxidation states of metals. I understand how to find the oxidation state of a metal in a compound, that's pretty straightforward. What I'm interested in is finding possible oxidation states given only the name of the metal. For example, Cu has possible...

I'm trying to wrap my mind around the concept of metals dissolving in water under different electrical potentials. For example, platinum is know to dissolve in liquid water when subjected to 0.65-1.1V. Why does this happen? I'm guessing it has something to due with water being so polar but why...

Metals with what type of crystal lattice less prone to brittle fracture? Why?

Homework Statement Transition metal species are known that contain multiple metal-carbon bonds, for example, M=CH2. Describe how the π portion of the M=C bond would be formed using a pure d orbital on M and in what plane the protons on the CH2 group would lie. (A d orbital is employed because...

Hi all In the following link it says: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/thercond.html "For metals, the thermal conductivity is quite high, and those metals which are the best electrical conductors are also the best thermal conductors. At a given temperature, the thermal and...

Hi, I'm a student learning Solid State Physics and in a chapter of Classical Free Electron Theory of Metals in the textbook, it mentions "Since in the absence of a (electric) field there can be no net current, it is clear that the average thermal velocity over the equilibrium (thermal velocity)...

Homework Statement The inner diameter of a steel ring is 2.0000 cm, and the diameter of an aluminum disk is 2.0100 cm. Both are at 430 degrees C. At what common temperature will the disk t precisely into the hole in the steel ring? alpha(Steel) = 1.3e-5 alpha(Al) = 1.9e-5 Homework...

Im guessing it's something to do with their metallic bonding of sorts?

If a circular beam consists of two separate metals, both having different inner and outer diameters, and one engulfs the other, how is the amount of twist able to be determined when the beam is connected at both ends to walls to form a composite shaft and is subjected to a torque? I Know that...

Homework Statement Show that, 'In p-block and d-block metals their carbonates,sulphides and hydroxides are insoluble" I understand that all carbonates are insoluble(except the alkali metal carbonates), also that all sulphides are insoluble,but it's the solubilty of hydroxides that I'm...

Just want to make sure my understanding is correct... Here it goes: 1. Metals have free electrons, which can be in a myriad of energy levels, including those corresponding to the full range of frequencies in the visible region of the spectrum. 2. Light shone on a piece of metal thus...

Hello all, I was wondering if there was a way to calculate the reflectivity of differing wavelengths of light hitting an element based upon its physical properties. I know that it is based on how the atoms of the material are excited based upon the wavelength hitting it. I eventually want to...