Why elements are arranged according to atomic number rather than atomic mass in the periodic table

Mendeleev placed certain elements not in order of increasing atomic mass so that they could fit into the proper groups (similar elements have similar properties) of his periodic table.

Explanation:

can you attach a picture of the lettuce? : )

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be