The first and a recent experimental determination of Avogadro's number
Resumen
ABSTRACT
It has been almost two centuries since Avogrado presented his
hypothesis, then, more than fifty years later Austrian Loschmidt
developed a method for measuring the diameter of air molecules which
was a big step for calculating a first approximation of the amount of
molecules or atoms per unit volume. Computing Avogadro’s with
Loschmidt’s diameter results give ten times the real value. It was until
the beginning of the 19th century when Jean Perrin measured an
accurate value of Avogadro’s constant, which is the amount of
elementary entities in one mole of substance. After him, many scientists have measured this constant using more accurate methods, one of them is the X ray diffraction method, which can reach accuracy of 99.99% as using 28Si.
Key words: Avogadro’s constant, Avogadro’s number, Loschmidt,
Texto completo:
PDFReferencias
The Basic of Atoms, Moles,
Formulas, Equations and
Nomenclature. Avogadro's Number
and the Mole, Chapter 2. Ed. Steve
Lower. [online].
Available: http://www.chem1.com/a
cad/webtext/intro/MOL.html [acces
sed December 14, 2009].
Mohr, P. J.; Taylor, B. N.; Newell,
D. B. (2008). CODATA
Recommended Values of the
Fundamental Physical Constants:
Rev. Mod. Phys. 80: 633–730.
Avogadro, A. (1811). Essai d'une
manière de déterminer les masses
relatives des molecules elementaires
des corps, et les proportions selon
lesquelles elles entrent dans ces
combinaisons. Journal de
Physique 73: 58–76.
Hyperphysics (2009). Kinetic Gas
Theory, Mean Free Path [online].
Available:http://hyperphysics.phy‐a
str.gsu.edu/hbase/Kinetic/menfre.ht
ml [accessed November 2009].
Loschmidt, J. (1865). Zur Grösse
der Luftmoleküle Sitzungsberichte
der kaiserlichen Akademie der
Wissenschaften Wien 52(2): 395–
Becker, P., Friedrich, H., Fuji, K.,
Giardini, W., Mana, G., Picard, A.,
Pohl, H.J., Riemann, H. and
Valkiers, S. (2009). The Avogadro
constant determination via enriched
silicon‐28 Meas. Sci.Technol. 20
(9): 2002.
Maxwell, J. C. (1873).
Molecules. Nature 8: 437–441.
Darwin, S. C. (1956). The
Rutherford Memorial Lecture,
The Discovery of Atomic
Number. Proc. Roy. Soc. A 236:
-296.
Loschmidt, J. (1865). Sitzber. Wien.
Acad. 52 (II): 395.
Maxwell, J. C. (1873).
Scientific
Papers. Nature 8: 298‐343.
Perrin, J. (1909).
Mouvement brownien et réalité
moléculaire Annales de Chimie et
de Physique 8e Série 18: 1–114.
Millikan R A 1917 A new
determination of e, N, and related
constants Phil.Mag. 34: 1‐30
Rutherford, E. and Geiger,
H. (1909). An electric method to
count alpha‐particles emitted from
radioactive substance. Phys.
Z. 10: 1‐6.
Du Nouy, P. L. (1924). The
surface equilibrium of colloidal
solutions and the dimensions of
some colloidal molecules Science
: 580-582.
National Institute of
Standards and Technology (2010).
The NIST Reference on constants,
units and uncertainty. Available:
http://
physics.nist.gov/cuu/Constants/inde
x.html [accessed September 2010]
Tulane University. (2009).
X-ray crystallography [online].
Available:
http://www.tulane.edu/~sanelson/ee
ns211/x-ray.htm [accessed
November 2009].
Becker, P. (2009).
Determination of the Avogadro
constant – A contribution to the
new definition of the mass unit
kilogram. Eur. Phys. J. Special
Topics 172(1): 343-352.
Absolute Astronomy,
Atomic weight, [online].
Available:http://www.absoluteastro
nomy.com/topics/Atomic_weight [a
ccessed November 2009].
Fujii, K., Waseda, A.,
Kuramoto, N., Mizushima, S.,
Becker, P., Bettin, H., Nicolaus, A.,
Kuetgens, U., Valkiers, S., Taylor,
P., De Bievre P., Mana, G., Massa,
E., Matyi, R., Kessler, E.G., Jr. and
Hanke, M. (2005). Present State of
the Avogadro Constant
Determination from Silicon Crystals
with Natural Isotopic
Compositions.IEEE Transactions
on Instrumentations and
Measurements 54(2): 854-859.
Enlaces refback
- No hay ningún enlace refback.
Naturaleza y Tecnología, revista electrónica de la División de Ciencias Naturales y Exactas del campus Guanajuato, Universidad de Guanajuato. En ella se reciben para su revisión y arbitraje, artículos originales de investigación, artículos de revisión sobre temas actuales de investigación, así como ensayos sobre diversas temáticas del mundo científico y académico en las áreas de la química, matemáticas, ingeniería, astronomía, biología y farmacia, dentro del ámbito que comprenden las ciencias naturales y exactas, siendo requerido que no hayan sido publicadas o en proceso de publicación en otras revistas. Cuenta también con un Facebook de notas científicas de actualidad como apoyo a la actividad académica de la comunidad universitaria y para conocimiento del público en general como parte de un programa de divulgación científica y tecnológica.
.