Which Elements Belong in Group 3?

摘要

In a commentary published in this Journal Laurence Lavelleargues that the recent trend found in many textbooks, to placelutetium and lawrencium in group 3 of the periodic table insteadof lanthanum and actinium, is a mistake (1). Lavelle correctlypoints out that recent theoretical predictions suggest a newconfiguration of [Rn]5f~(14)7s~27p~1,rather than [Rn]5f~(14)6d~17s~2,for lawrencium and considers that this configuration weakensthe claim that the element should be placed in group 3. It isunfortunate that of the four studies cited by Lavelle (2-5) tosupport the new configuration of lawrencium only one of themactually does so in a convincing manner while, one does not evenmention lawrencium (5), and another one actually concludesagainst the new configuration (3).