sentences: the order of the elements in periodic table is determined by the atomic number of the elements
docs: ionic_order is order. list_of_elements is list. identification_particle is atom. periodic_table is table. phosphorus_atom is atom. iron_atom is atom. poly_atomic_chemical_object is group_of_atoms. atomic_number is number. group_of_atoms is group_of_chemical_objects. each_element_in_periodic_table has number_associated_with