Uncertain natural constants
To re-calculate the Avogadro constant, researchers in Geel used a perfect single crystal of silicon which was cut to a near perfect cube or ball of at least half a kilo. Silicon was the best choice for this calculation as it can be grown with very few impurities. However, as the ratio between its isotopes varies, the molar mass of silicon cannot be regarded as a natural constant, and it is re-calculated every two years by an international committee. The hope is to further reduce the uncertainty to the value of the molar mass of silicon, and consequently the value of the Avogadro constant, by a factor of ten.
Bibliographic Reference: Article: Natuur & Techniek, Vol. 11 (1992) pp. 878-879
Record Number: 199310517 / Last updated on: 1994-11-29
Original language: nl
Available languages: nl