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 ...

Standard atomic weights, those numbers emblazoned under the elements on the periodic table, were once thought of as unchanging constants of nature. But researchers have tweaked the atomic weights of ...

Chlorine naturally exists as two isotopes, \(_{17}^{35}\textrm{Cl}\) (chlorine-35) and \(_{17}^{37}\textrm{Cl}\) (chlorine-37). The abundance of chlorine-35 is 75% ...

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) ...

Ten elements that help make up the universe, including the carbon our biology is based on and the oxygen in the air we breathe, are now getting changed in an unprecedented way — they are getting their ...

WHEN U.S. businessmen contemplate the peacetime uses of atomic energy, the talk revolves around huge nuclear-power plants to generate electricity. But while the nation’s first large-scale ...