
	Where results make sense

Topic: Avogadro constant

Related Topics

Amedeo Avogadro

Albert Avogadro

Avogadro crater

Boltzmann constant

mathematical constants

magic constant

fine structure constant

Benjamin Constant

Euler Mascheroni constant

Constant Fornerod

Jean Ren Constant Quoy

equilibrium constant

In the News (Wed 16 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Physical constant
		It can be constrasted to a mathematical constant which is a fixed number that does not directly involve a physical measurement.
		There are many such constants used in science, some of the most famous of which being: Planck's constant, the gravitational constant and Avogadro's constant (better known as Avogadro's number).
		Constants can take many forms; some, such as the Planck length represents a fundamental physical distance, others such as the speed of light signifies the maximun speed limit of the universe, yet others are dimensionless quantities such as the fine-structure constant which embodies the interaction between electrons and photons.
	www.ebroadcast.com.au /lookup/encyclopedia/ph/Physical_constant.html (158 words)

	Avogadro's number - Wikipedia, the free encyclopedia
		For this reason, Avogadro's number is not considered a fundamental constant in the strictest sense.
		Avogadro's number can be regarded as a conversion factor between the microscopic mass system (atomic mass units or Daltons) and the kilogram system.
		One modern method is to calculate Avogadro's number from the density of a crystal, the relative atomic mass, and the unit cell length determined from x-ray crystallography.
	en.wikipedia.org /wiki/Avogadro's_number (1333 words)

	Highbeam Encyclopedia - Search Results for Avogadro,
		Avogadro, Amedeo, conte di Quaregna, 1776-1856, Italian physicist, b.
		In 1811 he advanced the hypothesis, since known as Avogadro's law, that equal volumes of gases under identical conditions of pressure and temperature contain the same number of molecules.
		Avogadro's number ävÅgä´drÅ [for Amedeo Avogadro ], number of particles contained in one mole of any substance; it is equal to 602,252,000,000,000,000,000,000, or in scientific notation, 6.02252×10 23.
	www.encyclopedia.com /SearchResults.aspx?Q=Avogadro, (601 words)

	Home page of Avogadro
		His father was a distinguished lawyer and civil servant, becoming a senator of Piedmont in 1768, and was appointed advocate general to the senate of Vittorio Amedeo III in 1777.
		In 1806, Avogadro was appointed demonstrator at the Academy of Turin, and in 1809 became professor of natural philosophy at the college of Vercelli.
		The chair was eventually reestablished in 1832, and Avogadro was reappointed to the position in 1834.
	www.bulldog.u-net.com /avogadro/avoga.html (1420 words)

	Avogadro (Site not responding. Last check: 2007-10-22)
		Amedeo Avogadro was born in Torino to a noble ancient family of Piedmont, Italy.
		Avogadro held public posts in statistics, meteorology, and weights and measures (he introduced decimal metric system in Piedmont) and was a member of the Royal Superior Council on Public Instruction.
		Avogadro's Law implies that the relationship occurring between the weights of same volumes of different gases (at the same temperature and pressure) corresponds to the relationship between respective molecular weights.
	www.celebrities-site.com /results/index.php?title=Avogadro (941 words)

	Some Notes on Avogadro's Number, 6
		Amadeo Avogadro (1776-1856) was the author of Avogadro's Hypothesis in 1811, which, together with Gay-Lussac's Law of Combining Volumes, was used by Stanislao Cannizzaro to elegantly remove all doubt about the establishment of the atomic weight scale at the Karlsruhe Conference of 1860.
		Avogadro's important hypothesis on the identity of the numbers of molecules in equal volumes of different gases at the same pressure and temperature was formulated in 1811, and is appropriately associated with his name; but Avogadro made no quantitative estimate of either of the above-mentioned constants.
		The first actual estimate of the number of molecules in one cubic centimetre of a gas under standard conditions was made in 1865 by Loschmidt, and from this the number of molecules (atoms) in a gram molecule (atom) was later evaluated.
	iweb.tntech.edu /chem281-tf/avogadro.htm (989 words)

	AMEDEO AVOGADRO (Site not responding. Last check: 2007-10-22)
		Avogadro’s hypothesis, in conjunction with Gay-Lussac’s law should have allowed the molecular formulae and atomic weight of gases to be determined experimentally, but Avogadro’s paper on this subject attracted very little attention, since it was supported by so little experimental evidence.
		The Avogadro constant is a huge number, and one may ask, “how was it ever derived?” It can be determined from X-Ray diffraction studies.
		The Avogadro constant, L, = volume of one mole of atoms/volume of one atom.
	www.stormpages.com /aboutchemists/avogadro.html (962 words)

	Ideal Gas Law
		In the kinetic theory of gases, there are certain constants which constrain the ceaseless molecular activity.
		Avogadro's number is the number of molecules in a mole of any molecular substance.
		A mole (abbreviated mol) of a pure substance is a mass of the material in grams that is numerically equal to the molecular mass in atomic mass units (amu).
	hyperphysics.phy-astr.gsu.edu /hbase/kinetic/idegas.html (1049 words)

	Australian Centre for Precision Optics
		The proposition of the Avogadro Project is to redefine the kilogram in terms of the Avogadro constant.
		The Avogadro constant itself is obtained from the ratio of the molar mass to the mass of an atom.
		Currently the Avogadro constant is known to an uncertainty of approximately 0.1 ppm.
	www.tip.csiro.au /IMP/Optical/avogadro.htm (758 words)

	Avogadro's hypotheses: Teaching notes
		Notes: Amedeo Avogadro's (1776-1856) principal contribution to chemistry was a paper in which he advanced two hypotheses: (1) that equal volumes of gas contain equal numbers of molecules and (2) that elementary gases such as hydrogen, nitrogen, and oxygen were composed of two atoms.
		Avogadro's famous paper was an attempt to reconcile Dalton's atomic hypothesis with Gay-Lussac's results on combining volumes.
		Avogadro was right, but it would take about 50 years and the clear exposition of Cannizzaro before the chemical world realized it.
	web.lemoyne.edu /~giunta/classicalcs/avogadronote.html (560 words)

	Avogadro Constant (Site not responding. Last check: 2007-10-22)
		The Avogadro Constant, L is a constant number used to refer to atoms, molecules, ions and electrons.
		Likewise, the relative molecular mass expressed in grams is the mass of the Avogadro Constant of molecules.
		As an example, 23 g of sodium contain the same number of atoms as there are molecules in 17 g of ammonia.
	www.avogadro.co.uk /definitions/avogconst.htm (102 words)

	Kilogram to be redefined. - 4Forums.com
		However, Avogadro's number is still a fundamental constant: all constants depend on the units used and on the definition of the units, and therefore, such a dependence does not exclude that a constant can be called fundamental.
		The constants are also used to design and calibrate quantum-based measurement systems that are becoming important in the development of various technologies and in trade that relies increasingly on electronic testing, environmental monitoring, and quality control.
		To date, the most accurate experimental value of the Avogadro constant, based on the fixed mass of the kilogram prototype in Paris, is 6.022141527 x 10^23 per mole of particles (such as atoms or molecules).
	www.4forums.com /political/showthread.php?t=6034 (1998 words)

	Vacuum History & Technology
		Avogadro's number is the number of molecules in one gram-molecular-weight of any substance.
		The Boltzmann constant, k, is a fundamental constant of physics occuring in nearly every statistical formulation of both classical and quantum physics.
		This empirical relation, formulated by Boyle in 1662, states that the pressure (p) of a gas varies inversely as its volume (v) at constant temperature; in equation form, pv=k, and is a constant.
	www.mcallister.com /vacuum.html#avogadro (2681 words)

	Numerical Constants - Mathematics & Physics - Numericana
		The attribution of this irrational constant to Ramanujan was made by Simon Plouffe, as a monument to a famous 1975 April fools column by Martin Gardner in Scientific American (where it was claimed that the above had been proven to be exactly an integer, as conjectured by Ramanujan in 1914 [sic!]).
		Some other set of independent constants could have been used to define the 7 basic units (for example, a conventional value of the electron's charge could replace the conventional permeability of the vacuum) but the following one was chosen after careful considerations.
		Although precise determinations of Avogadro's constant were mentioned in the discussion leading up to that resolution, the watt balance approach was considered more promising.
	home.att.net /~numericana/answer/constants.htm (5480 words)

	[No title]
		Although the proposed re-definition of the kilogram (using the Planck constant) would be more directly implemented using the watt balance, the alternative method could still be used if additional calculations were made using the theoretical relationship between the Planck and Avogadro constants.
		This constant, together with the Avogadro constant, is used in, for example, studies of gases and semiconductors, and serves as a link between the everyday and microscopic worlds.
		This is a very large constant used in chemistry and physics, currently representing the number of atoms in 12 grams of carbon.
	www.nist.gov /public_affairs/newsfromnist_beyond_the_kilogram.htm (1839 words)

	Vacuum Scientists (Site not responding. Last check: 2007-10-22)
		He was a physicist who first set forth the hypothesis known as Avogadro's Law, which states that equal volumes of gasses or 'vapours', at the same temperature and pressure contain the same number of molecules.
		AVOGADRO'S LAW, a statement that under the same conditions of temperature and pressure, equal volumes of different gasses contain an equal number of molecules.
		In the metre-kilogram-second (mks) system of units, Avogadro's constant is the number of molecules in one kilogram-mole of a substance, defined as the molecular weight in kilograms.
	vacuumscientists.com (373 words)

	STARRY BLUE * Astronomy Glossary - Star Gazers - The Heavens and the Earth.
		Avogadro’s constant, however, must be determined experimentally, for example by counting the number of atoms in a crystal.
		The reciprocal of Avogadro's constant is numerically equal to the unified atomic mass unit, u, that is, 1/12 the mass of the carbon 12 atom.
		It is only applicable to ohmic resistors, those whose resistance R is constant over the range of interest and V obeys a strictly linear relation to I. Materials are said to be ohmic when V depends linearly on R. Metals are ohmic so long as one holds their temperature constant.
	www.starryblue.com /glossary.html (8024 words)

	Gas Laws: Avogadro's Law (Site not responding. Last check: 2007-10-22)
		Boyle's Law states that the product of the pressure and volume of a gas is a constant for a constant amount of gas and temperature.
		Charles's Law (sometimes called the Gay-Lussac Law) states that the volume of a gas is directly proportional to the temperature of the gas, provided the amount of gas and pressure are held constant.
		These studies led Avogadro to address the question of how the amount of gas affect the volume of the gas and how best to think about the amount of a gas.
	www.chm.davidson.edu /ChemistryApplets/GasLaws/AvogadrosLaw.html (759 words)

	Ever thought about the Avogadro's Number?
		Those of you out there who think the Avogadro's Number is a universal constant, think again.
		The name "Avogadro's Number" is just an honorary name attached to the calculated value of the number of atoms, molecules, etc. in a gram mole of any chemical substance.
		The best modern values for what we now call "Avogadro's Number" are the result of the x-ray diffraction measurement of lattice distances in metals and salts.
	www.angelfire.com /zine/chemistry/avogadro.html (314 words)

	[No title] (Site not responding. Last check: 2007-10-22)
		Avogadro's constant times the number of moles of an atom, molecule, ion etc. gives the number of individual entities present.
		By definition, its value depends on how accurately we can determine the number of carbon atoms in 1 mol of carbon-12, so it will periodically refined as our experimental skills increase (or better ways of statistically interpreting the data we have already).
		Avogadro's number is Avogadro's constant minus the units.
	orac.sunderland.ac.uk /~hs0bcl/gg/avogadro_s_constant.htm (92 words)

	Chemistry International -- Newsmagazine for IUPAC
		The uncertainties associated with the best estimates of the fundamental constants have mostly been falling by roughly an order of magnitude each 10 years, as new and improved experimental measurements make it possible to determine the constants with ever greater precision.
		The most interesting constants for chemistry from the new 2002 best estimates, comparing the 1986, 1998, and 2002 values, can be viewed in the accompanying table (pdf file).
		These constants are described as the 2002 best estimates, although the values have only just been released in December 2003, because the cut-off date for data included in the analysis was 31 December 2002.
	www.iupac.org /publications/ci/2004/2603/iw3_mills.html (814 words)

	General Chemistry Online: Glossary: Gases (Site not responding. Last check: 2007-10-22)
		A fundamental constant equal to the ideal gas law constant
		The volume of a gas is directly proportional to its temperature in kelvins, if pressure and amount of gas remain constant.
		A constant R equal to PV/(nT) for ideal gases
	antoine.frostburg.edu /chem/senese/101/gases/glossary.shtml (975 words)

	MW - The Weathers Constant
		The Weathers Constant, W, can be used in many areas of mathematics, economics, and computer science, and biology.
		Unlike some other, unwieldy physical constants, the Weathers Constant is short, easy to use, and quick to memorize.
		In short, the Weathers Constant is useful for many areas of science and every day life.
	www.matthewweathers.com /year2004/weathers_constant.htm (359 words)

	Chapter 14. Boltzmann's Constant
		Therefore, in SE units, the value of Boltzmann's constant is an electron's rest-mass energy divided by its threshold temperature for a value of unity.
		The value of Boltzmann's constant in SG units is the same as it is in SE units because both the masson's rest-mass energy and threshold temperature are greater than those of the electron by the same factor
		We see that Avogadro's number is a dimensionless conversion factor from one unit of mass to another and its magnitude, therefore, must be one.
	www.writword.com /unituniv/c14.htm (248 words)

	Avogadro's Number (Site not responding. Last check: 2007-10-22)
		Stanislao Cannizzaro to elegantly remove all doubt about the establishment of the atomic weight scale at the Karlsruhe Conference of 1860.
		This number is frequently referred to as "Avogadro's Number," the term "Loschmidt's Number" being then reserved for the number of molecules in a cubic centimetre of a gas under standard conditions.
		That the number today has 8 significant figures is a testament to the quality of modern experimental methods.
	gemini.tntech.edu /~tfurtsch/scihist/avogadro.htm (962 words)

	Faraday constant - a definition from Whatis.com
		The Faraday constant represents the amount of electric charge carried by a one mole, or Avogadro's number, of electrons.
		It is an important constant in chemistry, physics, and electronics, and is commonly symbolized by the italic uppercase letter F.
		The Faraday constant can be derived by dividing the Avogadro Constant, or the number of electrons per mole, by the number of electrons per coulomb.
	whatis.techtarget.com /definition/0,,sid9_gci863897,00.html (142 words)

	How many atoms are in the human head?
		Avogadro was an Italian Physicist who first described the Avogadro constant as a hypothesis in 1811.
		He was trying to understand why in chemical reactions involving gases the observation that equal volumes of different gases had the same number of moles.
		The idea that a mole of any substance has exactly the same number of atoms (or molecules) no matter what the substance is made of was explained by Avogadro and his name has stuck to his number ever since.
	education.jlab.org /qa/mathatom_03.html (459 words)

Try your search on: Qwika (all wikis)