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 ...

I was surprised that C&EN would devote two columns to the letter by Harvey Carroll on the matter of atomic weight versus atomic mass (C&EN, Jan. 24, page 4). I realize the majority of the informed ...

Let's talk Einstein and Nuclear Physics. What does E=MC2 actually mean? Why is it useful? It's time for our second to final Physics episode. So, let's talk Einstein and Nuclear Physics. What does ...

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 ...

The electron has been weighed with unprecedented precision, researchers report February 19 in Nature. Its new and improved mass, 17 times as precise as the previous best estimate, is 0.000548579909067 ...

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 ...

What is the weight of a proton? Scientists from Germany and Japan have made an important step toward better understanding this fundamental constant. By means of precision measurements on a single ...

Physicists in Germany say they have made the world’s most precise measurement of the deuteron mass by comparing it to the mass of the carbon-12 nucleus. The new work, which was carried out by ...