41. The same problem may occur with atomic weight based definitions. 42. In practice, only 11 of the mononuclidic elements are used in standard atomic weight metrology. 43. But his exact position on atomic weight is disputed. 44. The atomic weight of an atom minus it's atomic number is the number of neutrons. 45. Atomic mass figures are thus commonly reported to many more significant figures than atomic weights . 46. The date was chosen in recognition of the atomic weight of hydrogen ( 1.008 ). 47. These isotopes can have different atomic weights , depending upon the number of neutrons in the nucleus. 48. Claus managed not only to isolate ruthenium, but also determine its atomic weight and chemical properties. 49. His measurements showed that the two samples had different atomic weights , supporting the concepts of isotopes. 50. Isotopes are atoms of the same element that have similar chemical properties but different atomic weights .
