If h¹, is the first in the periodic table in beryllium mass number for does it keep going down, in two other metals and gases, 8th grade question

Iam not going to tell you

Hello thereone of the following properties was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version. which property fits this description? answer: atomic mass  was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

Answer-ide.

Answerchemical;