Why are there empty spaces in the rows on the periodic table?

Question

A. So that elements with similar properties are aligned in the same column
B. So that elements with similar masses are right next to each other
C. Because the elements on the periodic table are arranged by order of discovery
D. Because elements of the same size are found in the same rows

Answer 1

The correct answer is: A. So that elements with similar properties are aligned in the same column.

The periodic table is organized primarily by atomic number, which results in elements with similar chemical properties being placed in the same columns (groups or families). The empty spaces in the periodic table indicate where elements are placed according to their properties, even if they have not yet been discovered or synthesized.