Web edition: February 26, 2010
Print edition: March 13, 2010; Vol.177 #6 (p. 4)
New weight for silver will not affect dimes — An atom of silver weighs less than previously thought, but this new finding of the National Bureau of Standards will not affect the silver dimes in your pockets. A dime will still be worth ten cents. The new atomic weight of silver was set at 107.873 through accurate measurements with a mass spectrometer. The atomic weight currently used is 107.880. The more precise atomic weight of silver may mean that the atomic weights of other elements may have to be adjusted.… What makes the new measurement significant is the fact that the mass spectrometer was calibrated to extraordinary accuracy through use of known mixtures of the two highly purified silver isotopes.