Final answer:
The Periodic Table is arranged such that elements with similar chemical properties are in groups, and horizontal rows are called periods. This reflects similarities in electron configurations and the number of valence shells.
Step-by-step explanation:
One characteristic of the organization of the Periodic Table is that elements with similar chemical properties are arranged in vertical columns called groups or families. Elements in the same group share similar electron configurations, particularly the same number of valence electrons, which accounts for their similar properties. The Periodic Table is also organized into horizontal rows known as periods, which correlate with the number of valence electron shells.
The arrangement is based on each element's atomic number, that is, the number of protons in an atom's nucleus. It is important to note that the elements are not arranged diagonally nor are they organized alphabetically or by volume; their arrangement is specifically meant to reflect their atomic structure and chemical properties.