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 periodic table was arranged by atomic mass, and this nearly always gives the same order as the atomic number. However, there were some exceptions (like iodine and tellurium, see above), which didn ...

The number of subatomic particles in an atom can be calculated from the atom's atomic number and mass number. The periodic table - AQA Mendeleev made an early periodic table. In the modern ...