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 ...

Nineteen elements on the periodic table — including gold, cadmium, arsenic and aluminum — are getting their atomic weights adjusted. The International Union of Pure and Applied Chemistry (IUPAC) ...

For the first time those little numbers that appear beneath some of the commonest elements in the periodic table boxes are about to change from a single value to an interval of numbers An ...

High-precision measurements of the mass of the deuteron, the nucleus of heavy hydrogen, provide new insights into the reliability of fundamental quantities in atomic and nuclear physics. This is ...

A new definition of the kilogram is required, an international team of scientists contends. The current one is imprecise, they say, because it is not linked to an unvarying property of nature. The ...