Metals Definition and 318 Threads

Only metals undergo photoelectric effect?

Hello, I have a question about conduction in metals. I guess you all know a common pedagogical picture where an electron bands are drawn as ~ cosine curves in 1D or E_0 - cos(k_x) - cos(k_y) in 2D. Now, in metals , we were told that the Fermi surface passes through the band. Therefore...

I have some car engine related questions, but basically just physics. -Do different specific heat capacities have anything to do with how certain materials resist heat? I know that on some engine compartments there is gold wrapping because it resists heat best, but it has a low specific...

Homework Statement for a science experiment i am required to write relevant chemical equations to reactions that have occurred. I am having trouble showing the corrosion of iron, aluminum and copper in acetic acid and citric acid. Homework Equations heres what i have so far: Fe + 2...

I found this article on the web, describing how metals set up electrode potential in water or solution. How I see it the whole explanation makes sense to me, but I am not sure if its the right explanation. Could someone verify this? :confused:

Hi all, just a small question: why does a normal metal junction does not show a josephson like current when inserted in a squid setup? I guess it is something related to the coherence of the ground state...

When metals such as sodium react with an acid, a salt and hydrogen gas is produced. and we know for sure the oxidation state of sodium in the compound will be +1. But for other metals such as iron, when they rest with acids which oxidation state do I use? I'm unsure if I'm supposed to use the...

Is there fixed data for the threshold frequency of metals? For example, is it possible to find out the threshold frequency of iron or copper? OR does threshold frequency vary so greatly that with 2 blocks of iron, the theshold frequency could differ between them? Depending on the...

I am doing my revision and noticed that metals all have a molar heat capacity ~25 J/mol/K = 3R. Ionic solids such as NaCl and CaF2 however have different molar heat capacities. (~51 and 72 respectively) Why is this? there is no explination that my lecturer gave and I can't find it online but...

Hello, I'm having looots of trouble trying to find out the operative slip systems of hcp metals. the slip system is {001}<100> and in my notes it says that there are 3 slip systems and I don't see why! I'm guessing there's only one slip plane the (001) or (0001), and three directions. But the...

I was just wondering what the word is that describes the group of Metals and Non-Metals and Metalloids. like Hydrogen, Calcium, Carbon are all Elements Metals, Metalloids and Non-Metals are all _______ If there happens to be no such word please comment so.

Metals will react with acid to form a salt and water. But won't the metal also react with water to form an hydroxide? Similarly, when I put sodium metal into a zinc sulfate solution will displacement occur or will the sodium react with water? Thanks for the help!

To test the ability of Br2 and I2 to oxidize copper metal, the reactions take place between Br2water and I2 solution with copper: Cu (s) + Br2 (aq) -> Cu2+ (aq) + 2Br- (Aq) Cu(s) + I2 (methanol) -> Cu2+ (methanol) + 2I- (methanol). Write the net ionic equations describing the results of...

When I want to prevent iron from rusting, I use a more reactive metal such as magnesium and connect it to the iron. This protects iron from being rusted as the magnesium will transfer electrons into the iron when it rusts, thus reducing Fe2O3 into Fe metal. However, Mg will be oxidised to Mg2+...

Hi, sorry for the childish title. But this problem is supposed to be solved quantitatively using Laplace's equation, so it's not so straightforward. Homework Statement (a) Explain why it is possible to keep a teaspoon in a cup of water heated in a microwave oven without spark formation, but...

Hi, first post, so take it easy on me, I've had an idea for producing metallic objects with high surface area for several years, but lack the necessary physics knowledge to act on it or, really, inclination (and money) to go through years of school to gain such. The idea is as follows: A...

I found this on a webpage: In any transition element series, the number of unpaired electrons first increases from 1 to 5 and then decreases back to the zero .The maximum five unpaired electrons occur at Cr WHY?' doesn't it occur at MN??

Flame tests are used to test the color that a metal produces when heated and the electrons release energy when falling back to the ground state. This i understand, but why does the procedure only test the metal part of the salt? In other words, why does the anion part of the ionic compound not...

Metal detectors for searching metals in the ground How they work in one sentence explanation? and second, I've seen some frequency of about 8 kHz mentioned,could that be any possible health risk? Please discuss, thanks.

reaction of alkaline Earth metals with O2 i just got in my textbook that[FONT="Comic Sans MS"] Ba,Ca,Sr is kept in paraffin but Mg and Be are not as they form a protective coat of oxide on their surface.i don't get a clue about this .could anyone explain me this?

I am not a condensed matter physicist. Can someone explain the situation for free electrons in a metal to me. It seems like they would head straight for the nearest positively charged lattice nuclei. As it got very close <3 fermi it would radiate a lot because it is accelerating. So after a few...

Is there a physical explanation for why electrons move through a metal with a relatively low drift speed? Or is it just the observed phenomenon? I find it hard to visualise electrons moving relatively slowly through a metal despite the current flowing through it being quick...can anyone help? Thx

Can you point me to a good reference on metals. I want to understand for a metal like nickel with 28 electrons how many are free to move in the metal and how many are bound to the nuclei? Thanks.

What are four metals that spark if they are struck against themselves? I can't find this answer anywhere and really need to know! Thanks!

Good morning: I'm looking for information on electromagnets for attracting non-ferrous metals. One of the kids on the block is asking for assistance in research for a science fair project. She has a 1951 pamphlet describing the effect. And I found a construction article, but very little...

I was reading news article: http://www.sciencedaily.com/releases/2011/11/111115095911.htm Article explains in beginning that when star explodes as supernova, heavier elements are formed which later become part of new generations of stars. And in concluding paragraph, article says "reason why...

Thermocouples, dissimilar metals?? Hello everyone, this is my first post so go easy on me. Looking into making a thermopile and trying to decide what two metals to use, everywhere I look for thermocouple theory it says two dissimilar metals. My question is in what respect do they have to...

Some metals generate electrons when photons hit them, If so then what direction will the electron go into, will it be random and the uncertainty principle and quantum randomness. Or will it go in a direction relative to the point of impact from the photon, So if you shot a photon at an atom...

Hi, I understand for metals the conduction band is usually partially filled. However, at absolute zero, is the conduction band empty (for metals)? I'm asking this because as far as I know, the definition of valence band is "the highest occupied band at absolute zero" However, I have...

Homework Statement There are 4 identical metal balls: J, K, L, M. Initially, J has charge QJi = 0e, L has charge QLi = +42e, and M has charge QMi = -48e. The ball J touches the ball K, and they separate. Then, the ball J touches the ball L, and they separate. Then, the ball J touches the...

Metalloids such as silicon share similar properties to metals, yet the way that electrons are held in both materials are completely different. Whereas the electrons from silicon atoms are orbiting the nucleus, the outer shell of the electrons of metallic atoms are "stripped" from the atom...

So i was doing my school work earlier and i had trouble wrapping my head around this particular topic, even though i was able to finish all of it correctly, i want to make sure it sinks it well so i once again decided to approach these forums :) We were naming Ionic compounds, specifically...

Hello All, I am trying to build what is essentially an electrochemical cell which I will use to filter waste water and try to recover gold silver and copper among other metals on a High Surface Area Cathode like Carbon.I want this electronic filter to be selective about the metals recovered...

I saw this video on a car cleaning product. In it he talks about the improtance of pH balance and how it effects metals. I'm not a chemist, and it's been a long time since I took undergrad chemistry. You can see he does a little lab experiment with the metals in the various pH cleaning solutions...

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...

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 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.

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?