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 ...

Note that you can work out the number of neutrons by subtracting the atomic number from the mass number. In this example, it is 35 – 17 = 18 neutrons.