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Metals

A metal is an element, compound or alloy that is a good conductor of both electricity and heat. They are generally shiny, malleable and ductile. Some elements and compounds are not classified as metals unless under high pressures when they begin to act as metals.

Metallic substances atoms are closely positioned to neighboring atoms in either two possible arrangements. The first arrangement is body-centered cubic. In this arrangement, each atom is positioned at the center of eight other atoms. The second arrangement is face-centered cubic. In this arrangement, each atom is positioned in the center of six others. These two different arrangements form crystal structures. Structures of metals can change depending on the temperature.

Atoms from metallic substances can lost their outer shell electrons. This results in a free flowing cloud of electrons within their otherwise solid arrangement. It provides the ability of metallic substances to easily transmit heat and electricity. The solid characteristic of metals during this flow of electrons occurring is produced by electrostatic interactions between each atom and the electron cloud. This is called metallic bonding.

Metals are inclined to form cations through electron loss reacting with oxygen in the air to form oxides over various timescales. Transition metals (iron, copper, zinc) are slower to oxidize because they form passivation layers of oxide that protects the interior. Other metals such as palladium, platinum and gold, do not react with the atmosphere at all. This is due to the barrier layer of oxide which is formed on the surface which is impenetrable by further oxygen molecules. This allows those metals to retain their shiny appearance and good conductivity.

Alloys are a mixture of two or more elements, which the main component is a metal. Often pure metals are either to soft, brittle or chemically reactive for practical use. Combining different ratios of metals makes alloys have the desirable properties of the pure metals. Common alloys will incorporate aluminium, titanium, copper and magnesium.

Density: To find Density of solid using graduated cylinder.

Problem: A piece of solid metal weighing 322 grams is placed into a graduated cylinder, which is then filled with liquid mercury. The metal does not float. After weighing the cylinder and its contents the solid metal is removed and the cylinder is then filled with more liquid mercury to the same level as before. Now the cyli

Electrostatics: Field due to solid metal sphere.

A solid metal sphere with radius 0.460 m carries a net charge of 0.200 nC . Find the magnitude of the electric field at a point 0.106 m outside the surface of the sphere. Find the magnitude of the electric field at a point inside the sphere, 0.106 m below the surface.

Frictional Metal of Atomic Weight

Please see attachment. A frictional metal of atomic weight 27 has a density of 3000kg m^-3. The heat of fusion is 4*10^5J kg^-1 at the melting point (900k), and at the boiling point (1300k) the heat of vaporization is 1.20*10^7J kg^-1. For the solid, cp can be given by 750+0.5T in J kg^-1 and in the liquid cp is 1200J kg^-1 k

Skin Depth in Conductors

a. Show that the skin depth in a poor conductor (sigma << WE) is (2/sigma) (E/mu)^1/2 when independent of frequency. Find the skin depth (in meters) for (pure) water. b. Show that the skin depth in a good conductor (sigma >> WE) is lambda/2pi (where lambda is the wavelength in the conductor). Find the skin depth (in nanometer

Rate of heat conduction

A metal bar is used to conduct heat. When the temperature at one end is 100.0 degrees C and at the other is 20.0 degrees C, heat is transferred at a rate of 16 J/s. If the temperature of the hotter end is reduced to 80.0 degrees C, what will be the rate of heat transfer?

Scattering Mechanism in Metals

Consider the thermal conductivity K of a pure synthetic sapphire crystal that has a diameter of 3mm. (For sapphire delta D -1000 K , speed of sound - 10^4ms^-1, and for T <<delta D, cv - 10^-1 T^8 J M K^-1, delta D is the Debye temperature and T is the temperature). a. Discuss which scattering mechanism dominates the thermal

Magnetic flux threading a metal ring varies with time

The magnetic flux threading a metal ring varies with time t according to 3at^3-bt^2, with a = 7.7s^-3m^2T, and b = 2.8 s^-2m^2T. The resistance of the ring is 2.3 Ohms. Determine the maximum current induced in the ring during the interval from t1 = -2.3 s to t2 = 7.3 s. Answer in units of A