Maintain predictable orbital patterns. What force governs the motion and
patterns of objects in our solar system?
Orbital Plane
All planets in the solar
system orbit on the
same orbital plane
Mercup
Venus
Asteroid
Comet
** Many comets exist outside the orbital plane

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.