Final answer:
The periodic table arranges elements by increasing atomic number, with groups sharing similar valence electron configurations and chemical behaviors.
Step-by-step explanation:
The order of the elements in the periodic table is determined by an element's atomic number, which is indicated by the symbol Z. The atomic number represents the number of protons in the nucleus of an atom, giving each element its unique identity. According to the periodic law, there is a periodic repetition of the elements' chemical and physical properties when they are arranged by increasing atomic number. This arrangement allows the periodic table to be a valuable tool for predicting the behavior of elements, understanding their chemical properties, and identifying their electron configurations. Specifically, the table is organized into horizontal rows known as periods and vertical columns called groups. In the groups, elements share similar valence electron configurations, leading to similar chemical behaviors.