is conductivity a physical or chemical property
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A physical property is any measurable property the value of which describes a physical system's state. The changes in the physical properties of a system can be used to describe its transformations (or evolutions between its momentary states).
An object or substance can be measured or perceived without changing its identity. Physical properties can be intensive or extensive. An intensive property does not depend on the size or amount of matter in the object, while an extensive property does. In addition to extensiveness, properties can also be either isotropic if their values do not depend on the direction of observation or anisotropic otherwise. Physical properties are referred to as observables. They are not modal properties.
Often, it is difficult to determine whether a given property is physical or not. Color, for example, can be "seen"; however, what we perceive as color is really an interpretation of the reflective properties of a surface. In this sense, many ostensibly physical properties are termed as supervenient. A supervenient property is one which is actual (for dependence on the reflective properties of a surface is not simply imagined), but is secondary to some underlying reality. This is similar to the way in which objects are supervenient on atomic structure. A "cup" might have the physical properties of mass, shape, color, temperature, etc., but these properties are supervenient on the underlying atomic structure, which may in turn be supervenient on an underlying quantum structure.
List of properties
The physical properties of an object are defined traditionally in a Newtonian sense; the physical properties of an object may include, but are not limited to:
- boiling point
- electric charge
- electrical conductivity
- electrical impedance
- electric field
- electric potential
- flow rate
- Intrinsic impedance
- magnetic field
- magnetic flux
- melting point
- specific heat
- thermal conductivity
- heat transfer, conduction (or heat conduction) is the transfer of thermal energy between regions of matter due to a temperature gradient. Heat always flows from a region of higher temperature to a region of lower temperature, and results in the elimination of temperature differences by establishing thermal equilibrium. Conduction takes place in all forms of matter, viz. solids, liquids, gases and plasmas, but does not require any bulk motion of matter. In solids, it is due to the combination of vibrations of the molecules in a lattice or phonons with the energy transported by free electrons. In gases and liquids, conduction is due to the collisions and diffusion of the molecules during their random motion.
On a microscopic scale, conduction occurs as rapidly moving or vibrating atoms and molecules interact with neighboring particles, transferring some of their kinetic energy. Heat is transferred by conduction when adjacent atoms vibrate against one another, or as electrons move from one atom to another. Conduction is the most significant means of heat transfer within a solid or between solid objects in thermal contact. Conduction is greater in solids because the network of relatively fixed spacial relationships between atoms helps to transfer energy between them by vibration.
As density decreases so does conduction. Therefore, fluids (and especially gases) are less conductive. This is due to the large distance between atoms in a gas: fewer collisions between atoms means less conduction. Conductivity of gases increases with temperature. Conductivity increases with increasing pressure from vacuum up to a critical point that the density of the gas is such that molecules of the gas may be expected to collide with each other before they transfer heat from one surface to another. After this point conductivity increases only slightly with increasing pressure and density.
Thermal contact conductance is the study of heat conduction between solid bodies in contact. A temperature drop is often observed at the interface between the two surfaces in contact. This phenomenon is said to be a result of a thermal contact resistance existing between the contacting surfaces. Interfacial thermal resistance is a measure of an interface's resistance to thermal flow. This thermal resistance differs from contact resistance, as it exists even at atomically perfect interfaces. Understanding the thermal resistance at the interface between two materials is of primary significance in the study of its thermal properties. Interfaces often contribute significantly to the observed properties of the materials.
The inter-molecular transfer of energy could be primarily by elastic impact as in fluids or by free electron diffusion as in metals or phonon vibration as in insulators. In insulators the heat flux is carried almost entirely by phonon vibrations.
Metals (e.g. copper, platinum, gold,etc.) are usually the best conductors of thermal energy. This is due to the way that metals are chemically bonded: metallic bonds (as opposed to covalent or ionic bonds) have free-moving electrons which are able to transfer thermal energy rapidly through the metal. The "electron fluid" of a conductive metallic solid conducts nearly all of the heat flux through the solid. Phonon flux is still present, but carries less than 1% of the energy. Electrons also conduct electric current through conductive solids, and the thermal and electrical conductivities of most metals have about the same ratio. A good electrical conductor, such as copper, usually also conducts heat well. The Peltier-Seebeck effect exhibits the propensity of electrons to conduct heat through an electrically conductive solid. Thermoelectricity is caused by the relationship between electrons, heat fluxes and electrical currents. Heat conduction within a solid is directly analogous to diffusion of particles within a fluid, in the situation where there are no fluid currents.
To quantify the ease with which a particular medium conducts, engineers employ the thermal conductivity, also known as the conductivity constant or conduction coefficient, k. In thermal conductivityk is defined as "the quantity of heat, Q, transmitted in time (t) through a thickness (L), in a direction normal to a surface of area (A), due to a temperature difference (Î”T) [...]." Thermal conductivity is a material propertythat is primarily dependent on the medium'sphase, temperature, density, and molecular bonding. Thermal effusivity is a quantity derived from conductivity which is a measure of its ability to exchange thermal energy with its surroundings.
Steady state conduction is the form of conduction which happens when the temperature difference driving the conduction is constant so that after an equilibration time, the spatial distribution of temperatures (temperature field) in the conducting object does not change a
A chemical property is any of a material's properties that becomes evident during a chemical reaction; that is, any quality that can be established only by changing a substance's chemical identity. Simply speaking, chemical properties cannot be determined just by viewing or touching the substance; the substance's internal structure must be affected for its chemical properties to be investigated.
Chemical properties can be contrasted with physical properties, which can be discerned without changing the substance's structure. However, for many properties within the scope of physical chemistry, and other disciplines at the border of chemistry and physics, the distinction may be a matter of researcher's perspective. Material properties, both physical and chemical, can be viewed as supervenient; i.e., secondary to the underlying reality. Several layers of superveniency are possible.
Chemical properties can be used for building chemical classifications.
Examples of chemical properties
- Reactivity against other chemical substances
- Heat of combustion
- Enthalpy of formation
- Chemical stability in a given environment
- Preferred oxidation state(s)
- Coordination number
- Capability to undergo a certain set of transformations, for example molecular dissociation, chemical combination, redox reactions under certain physical conditions in the presence of another chemical substance
- Preferred types of chemical bonds to form, for example metallic, ionic, covalent
For example hydrogen has the potential to ignite and explode given the right conditions. This is a chemical property.
Metals in general do they have chemical properties of reaction with an acid. Zinc reacts with hydrochloric acid to produce hydrogen gas. This is a chemical property.
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Answers:utilise la m thode de r solution de probl me de Peano
Answers:ability to burn c ability to conduct electricity p ability to conduct heat p attraction to magnets p ability to corrode c explosiveness c ability to decompose c shape p solubility p reactivity c conductivity p mass p volume p absorbs heat p blowing up(explosion) c burning c change in odor c change in shape p change in color c condensation p evaporation p foaming usually c but if boiling p gives off heat usually c but if solidifying p gives off light(glows) c production of gas bubbles c formation of a precipitate c rusting c
Answers:Physical: almost colorless, less volatile than water, denser than water, more viscous than water, miscible in water. mp: -.41 deg C bp: 150.2 deg C density: 1.6434 g/cm3 (solid at -4.5 C) 1.4425 at 25C Viscosity: 1.245 centipoise (20C) vapor pressure (@ 25C) 1.9mmHg dielectric constant: (25C) 70.7 Electric conductivity (25C) 5.1E-8 ohm^-1 cm^-1 standard heat of formation -187.6 kJ/mol standard gibbs free energy of formation: -118.0 kJ/mol Chemical: spontaneously disproportionates decomposition strongly catalyzed by metal surfaces (Platinum, Silver) can act as oxidizing or reducing agent (in both acidic and basic solutions) evolves O2 when a reducing agent can undergo proton acid/base reactions to form peroxonium salts, hydroperoxides, and peroxides somewhat stronger acid than water (pKa=11.65) much weaker base than water (by a a 10^6 factor) used in the production of epoxides, propylene oxide, and caprolactones, hydroquinone, and many pharmaceuticals and food products environmental applications include pollution treatment by oxidizing cyanides and sulfides, and restoring aerobic conditions to sewage waters. replaces chlorine in industrial bleach because H2O and O2 decomp. products That should be a start.
Answers:From my favorite science website: Chem4kids Acid: A solution that has an excess of H+ ions. It comes from the Latin word acidus that means "sharp" or "sour". Base: A solution that has an excess of OH- ions. Another word for base is alkali. Aqueous: A solution that is mainly water. Think about the word aquarium. AQUA means water. Strong Acid: An acid that has a very low pH (0-4). Strong Base: A base that has a very high pH (10-14). Weak Acid: An acid that only partially ionizes in an aqueous solution. That means not every molecule breaks apart. They usually have a pH close to 7 (3-6). Weak Base: A base that only partially ionizes in an aqueous solution. That means not every molecule breaks apart. They usually have a pH close to 7 (8-10). Neutral: A solution that has a pH of 7. It is neither acidic nor basic. Strong Electrolyte A strong electrolyte is compound that ionizes one hundred percent in solution. Strong acids, bases, and salts are all strong electrolytes. Electrolyte Question: Proof Information Below http://library.thinkquest.org/3659/acidbase/electrolytes.html Certain substances that are called electrolytes produce ions when they dissolve in solution. Because these ions are free to move in solution, the solution conducts electricity. Ions can be produced in solution in either of two ways. Electrolytes can be either ionic compounds (i.e. sodium hydroxide, potassium nitrate) that dissolve in water, giving solutions of ions, or they may be covalent compounds that react with water and form ions in solution as a result. When an ionic substance such as NaCl dissolves in H2O, the water then separates the ions present in the NaCl crystal lattice. This process, known as dissociation, is shown below: Na+Cl-(s) --> Na+(aq) + Cl-(aq) When a polar covalent substance such as HCl dissolves in water, ions are created by the interaction between HCl and H2O molecules. This process, known as ionization is shown below: HCl(g) + H 2O(l) --> H3O+(aq) + Cl-(aq) Lastly, examples of acids and bases (Wikipedia) Perchloric acid HClO4 Hydroiodic acid HI Hydrobromic acid HBr Hydrochloric acid HCl Sulfuric acid H2SO4 (Ka1/first dissociation only) Nitric acid HNO3 Hydronium ion H3O+ or H+. For purposes of simplicity, H3O+ is often replaced in a chemical equation with H+. However, it should be noted that a bare proton simply does not exist in water but instead is bound to one of the lone pairs of electrons on the H2O molecule. This creates the hydronium ion and gives its single O atom a formal charge of +1. Some chemists include chloric acid (HClO3), bromic acid (HBrO3), perbromic acid (HBrO4), iodic acid (HIO3), and periodic acid (HIO4) as strong acids, although these are not universally accepted. Potassium hydroxide (KOH) Barium hydroxide (Ba(OH)2) Caesium hydroxide (CsOH) Sodium hydroxide (NaOH) Strontium hydroxide (Sr(OH)2) Calcium hydroxide (Ca(OH)2) Lithium hydroxide (LiOH) Rubidium hydroxide (RbOH)