There is a common misconception among educators, and even some metrologists, that the Avogadro constant _N_~A~ is (or should be) a pure number, and not a constant of dimension *N*^–1^ (where *N* is ...

WASHINGTON, D.C., July 14, 2015 -- An ongoing international effort to redefine the kilogram by 2018 has been helped by recent efforts from a team researchers from Italy, Japan and Germany to correlate ...

This release is available in German. A milestone in the international Avogadro project coordinated by the Physikalisch-Technische Bundesanstalt (PTB) has been reached: With the aid of a single crystal ...

How many atoms are there in a kilogram of silicon? This number is Avogadro’s constant and working out its value is one of the more important tasks that materials scientists face. Today, a group of ...

The world’s measurement system will be based on updated values for four fundamental constants of nature. A revised SI ( the International System of Units ) based fully on accurate values of these ...

I MUST plead guilty to the charge of not having made a very deep search of the older literature in connexion with the evaluation of ‘Avogadro's Number’. This name has only come into general use in ...

The kilogram may finally get a break from its yo-yo diet. An international team of scientists is closer to redefining the unit of mass based on fundamental constants, instead of a piece of metal in ...

In addition to other scientific units, the kilogram also is now defined by a natural constant. This is made possible by single crystals grown from highly enriched silicon-28. In addition to Ampere, ...

Relics in the form of rods, rulers, and weights go back thousands of years, suggesting that people have long cared about standardized measurements. Today, the International System of Units(SI) defines ...