In April 2015, an international team of researchers announced the measurement, for the first time, of the first ionization energy of lawrencium, a superheavy element of atomic number 103. The experimental result, published in the prestigious scientific journal Nature, led to the reopening of a long-standing debate that concerns the elements that should be part of group 3 of the periodic table. The aim of this paper is to introduce a new line of argumentation to elucidate this problem.