Explain these two terms (a)pseudo solid  (b)annealing?
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a) pseudo solid. An example would be when you mix a lot of corn starch to water, creating a matrix. When you stir it quickly, it cracks and breaks, but when you stir it slowly, it behaves as a liquid. So this pseudo solid has some solid properties, but really is a colloid liquid.\nb) Annealing. (metallurgy), a heat treatment that alters the microstructure of a material causing changes in properties such as strength and hardness. This process is done for steel and other alloys in machining high quality parts for aeronautics, tooling, etc.
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You are looking at a displacement reaction, in which the more reactive metal (Cu) is displacing the less reactive metal (Ag) from its salt solution (AgNO3).\nCu (s) + 2AgNO3 (aq) --> 2Ag (s) + Cu(NO3)2 (aq)\n\nHope this helps. :)
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Solid and in solids Diamond.\n\nSecond  Alummina and titanium carbide.
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In my years of teaching, it seems that everything in chemistry is related to stability.  The network solids are very stable structures and form strong bonds.  \n\nA melting point in chemical terms is when the physical property of heat is capable of changing the configuration of the bonds.  This configuration will be resistant to change if it is in a stable state, because the change to the liquid form is an increase in entropy (chaos).  Therefore a high temperature would be required to change the form.
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Answer 1:\n"Glasses" are amorphous solids, that is, they don't have a regular shape.\nEssentially the opposite of crystalline solids which have a defined shape.\nWhen you break a crystalline solid, it will give flat, well defined faces.\nCrystals melt or decompose at definite temps and the change from s to l\nis usually abrupt.  Glass (say window glass) will shatter into irregular\nfaces and curves.  There are many different kinds of glass and none really\nhave a melting point.  All pretty much have silicon dioxide as a principle\ningredient then something else added:  Here are some numbers...keep in mind\nthese are all SOFTENING  points and NOT melting points:\nsilica glass: 1580 Celsius   soda-lime glass: 695 C\nborosilicate glass: 820 C    aluminosilicate glass: 915 C\nleaded glass: 630 C\nWhat I'm trying to say is:  glass isn't a liquid.  It's a solid with so\nmany 'defects' that the order inherent in a crystal is absent.  When I\nsay defects, I'm talking at the molecular level, not physical scratches,\nand so on. You may want to recheck that 100 K number you presented.\nThat's 173 degrees Celsius below zero (-280 F)!\nAm I going to get some arguments about my stance?  I'll find out more\nfrom our resident glassblower here at the university.\n-Joe Schultz\n\nAnswer 2:\nI very much agree with J. Schultz's response...  Here are a couple\nof other observations:\nGlass is formed by melting silicon dioxide (SiO2) which has a\nmelting point of 1710 deg. C..  In its crystalline form, SiO2\nhas a very ordered structure with each Si atom bonded to 4 O atoms\nand each O atom attached to two Si atoms.  If the SiO2 is quickly\ncooled after being melted, the SiO2 "molecules" do not have a chance\nto get completely lined up in their solid crystalline form and thus\nan amorphous solid (glass) is formed.\nOften we like to categorize substances as gas, solid, or liquid..\nobviously, glass is somewhere between a solid and a liquid --\nsome scientists refer to it as a pseudo-solid\n-Dr. Brown
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Solid\nCopper melts at 1083ºC
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First you have to have understanding of their bonding.\n\nMetallic bond - Metallic bonding is the bonding within metals. It involves the delocalized sharing of free electrons among a lattice of metal atoms. These become delocalized electrons or sometimes called a Sea of Electrons surround a giant lattice of positive ions.\n\nWhy is it ductile?\n\nIt is ductile because the attracive forces between the free electrons and cations (positive ions) are very strong. However the cations are able to change its positions(ie change shape) but not seperated from the whole lattice structure.\n\nCeramic on the other hand is an ionic solid. Ionic bonds are a type of chemical bond based on electrostatic forces between two oppositely-charged ions. Often ionic bonds form between metals and non-metals.\n\ntake salt for example:\nhttp://www.geo.arizona.edu/xtal/geos306/9_2.jpg\n\nwhen the struture is changed as a result of impact (ie a piece of the block move downwards by one atom), the positive ions (Na+) changed its location, next to another Na+ ion. (same with the Cl- ion)so they repelled and causes the whole structure to fall apart (brittle).
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The solid phase.  Water is an exception.\nAlso some materials has more than one solid phase, such as carbon which has different structures and therefore different densities for graphic as opposed to diamond.
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a) 3SiO2 +2 Al --->3 Si + 2Al2O3\n\nb)AgNO3 +HCl---> AgCl +HNO3\n\nc) Mg + CuSO4 ---> MgSO4 + Cu\n\nd) Pb(NO3)4 +4 NaI --->4 NaNO3 + PbI4 (s)
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These metals are softer than others (ex. steel) and will self-anneal at room temperature, thus counteracting the strain hardening.
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This is a purely physical change of state from solid to liquid as a result of energy being added to the system.  There is an increase in entropy of the system.
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Metallic materials consist of a microstructure of small crystals called "grains" or crystallites. The nature of the grains (i.e. grain size and composition) determine the overall mechanical behavior of the metal. Heat treatment provides an efficient way to manipulate the properties of the metal by controlling rate of diffusion, and the rate of cooling within the microstructure. In carbon and low alloy steels, fast rates of cooling result in a high degree of hardness. In precipitation hardened alloys like 2000 series, 6000 series, and 7000 series aluminum alloys, as well as some superalloys and some stainless steels, fast cooling rates result in a softer metal. At these fast cooling rates, the alloying elements are trapped in solution and require a tempering to precipitate intermetallic particles, there by achieving maximum strength and hardness\n\nAnnealing is a technique used to recover cold work and relax stresses within a metal. During annealing, small grains recrystallize to form larger grains, and precipitates dissolve into the matrix. The result is a soft, ducile metal. When an annealed part is allowed to cool in the furnace, it is called a "full anneal" heat treatment. When an annealed part is removed from the furnace and allowed to cool in air, it is called a "normalizing" heat treatment.\n\nTo harden by quenching, a metal (usually steel or cast iron) must be heated into the austenitic crystal phase and then quickly cooled in oil, water, or brine. Upon being rapidly cooled, the austentite will transform to martensite, a hard brittle crystalline structure. Often a quenched metal is too hard, and must be tempered (heat treated at a low temperature) to impart some ductility.\n\nIf a peripitation hardend alloy is quenched, its alloying elements will be trapped in solution, resulting in a soft metal. Tempering a "solutionized" metal will alloy the alloying elements to diffuse through the microstructure and form intermetallic particles. These intermetallic particles will fall out of solution and act as a reinforcing phase, there by increasing the strength of the alloy. This process is called "artificial aging". Conversely, some alloys may be "naturally aged" in which the intermetallic particles form at room temperature. Naturally aging alloys are often stored in a freezer to prevent them from aging until needed.\n\nComplex heat treating schedules are often devised by metallurgists to optimize an alloy's mechanical properties. In the aerospace industry, a superalloy may undergo five or more different heat treating operations to develop the desired properties. This can lead to quality problems depending on the accuracy of the furnace's temperature controls and timer.\n\nCase hardening is a type of quenching heat treatment in which the surface of a part is heated (either with a flame or inductive heating) and then quenched. This imparts a hard surface to a part, without robbing it of ductility. Tools, blades, and bearings are often case hardened\n\nWhen the term is applied to aluminum alloys, however, its use frequently is restricted to the specific operations employed to increase strength and hardness of the precipitation-hardenable wrought and cast alloys. These usually are referred to as the "heat-treatable" alloys to distinguish them from those alloys in which no significant strengthening can be achieved by heating and cooling. The latter, generally referred to as "non heat-treatable" alloys depend primarily on cold work to increase strength. Heating to decrease strength and increase ductility (annealing) is used with alloys of both types; metallurgical reactions may vary with type of alloy and with degree of softening desired. \n\nOne essential attribute of a precipitation-hardening alloy system is a temperature-dependent equilibrium solid solubility characterized by increasing solubility with increasing temperature. The mayor aluminum
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Listen to IBL.  Metaraison's first and last sentences were right, but the transition from gas to solid is called deposition, not freezing.\n\nNames for phase transisitions:\ngas to liquid: condensation\nliquid to gas: boiling\ngas to solid: deposition\nsolid to gas: sublimation\nliquid to solid: freezing\nsolid to liquid: melting
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I'm sure this isn't the only material with this property.  \nDo you know what a phase diagram is?  If the line between the liquid and solid phases has a negative slope (goes down as you read it across) like the second phase diagram at this website: http://wine1.sb.fsu.edu/chm1045/notes/Forces/Phase/Forces06.htm\nAny material with a phase diagram that has the line between the liquid and solid phases as a negative slope becomes less dense (expands) when it freezes.  \nThe reason that water expands when it freezes is because when water crystallizes into ice, the structure leaves this pocket of emptyness in the middle of a ring of water molecules.  This makes the ice larger than the water it was when it was liquid.  Anything else that does this will also expand.
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the first link explains system boundary and the second is an explanation of computer simulations in the context of "conceptualizing a system".  hope this helps
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1.   Ag + KNO3 --> AgNO3 + K\n      single replacement means that a single element breaks a compound apart and joins with part of it--but which part--the positive or negative part?  It depends on what the single element is.  If it's a metal (#1 above), it will join with the negative part of the compound.  If it's a nonmetal (# 4 below), it will join with the positive part of the compound.\n4.  Cl2 + 2 KI --> 2 KCl + I2\nI'll leave you to have fun with the rest!
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I'm supposing that by R-value you mean resistance value.\n\nIf so, there are two separate formulas. \nFirst for R-values in series, meaning, materials which are layered: \n\nRtotal =R1 + R2 +...+ Rn\n\nFor R-values in parallel, meaning two or more materials side by side:\n\n(1/Rtotal) = 1/R1 + 1/R2 +...+ 1/Rn