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) ...

Part of Physics (Single Science) Unit 1: Atomic and nuclear physics Most of the mass and all of the positive charge of an atom is in the nucleus. Most of an atom is empty space, (a vacuum). In 1897, ...