Question

Scientists believe that interactions between atoms depend mostly on the arrangement of the outermost electrons in each atom. This theory is MOST supported by the observation of similar reactions among elements —
with a similar atomic mass
with a similar atomic number
in a group (column) of the periodic table
in a period (row) of the periodic table

Answer 1

I’m pretty sure it’s in a group (column) of the period table. Hope this helps :)))