Scientists use the periodic table to quickly refer to information about an element, like atomic mass and chemical symbol. The periodic table’s arrangement also allows scientists to discern trends in ...

The term ‘weighted mean mass’ takes into account the different contribution of each isotope to the overall mass. Relative atomic mass is not the same as mass number. Mass numbers close mass ...

The nucleus of each atom contains protons and neutrons. While the number of protons defines the element (e.g., hydrogen, carbon, etc.) and the sum of the protons and neutrons gives the atomic mass, ...

Atoms of different elements usually have different mass numbers, but they can be the same. For example, the mass number of argon atoms and calcium atoms can both be 40. The atomic number of a ...

February 7 is National Periodic Table Day, when we celebrate the efforts of scientists over the centuries to figure out how different elements ...