Thank you for bringing to my attention the recent International Union of Pure & Applied Chemistry report “Atomic weights of the elements 2009” (C&EN, Dec. 20 ...

How does one go about measuring the mass of an object? Mass is defined as the amount of matter an object contains. This is very different from weight, of course, as the mass of our object would remain ...

THAT the intra-atomic charge of an element is determined by its place in the periodic table rather than by its atomic weight, as concluded by A. van der Broek (NATURE, November 27, p. 372), is ...

Researchers have developed a new approach in optical atomic clocks that brings forth a major goal in science: the redefinition of a second. The fundamental unit of time could soon be based on ...

Alfredo has a PhD in Astrophysics and a Master's in Quantum Fields and Fundamental Forces from Imperial College London.View full profile Alfredo has a PhD in Astrophysics and a Master's in Quantum ...