Final answer:
The eight-element periodicity statement about the periodic table is false; periodicity is based on repeating trends of chemical properties due to the arrangement of valence electrons. Group 7 elements are very reactive, while Group 18 elements, or noble gases, are unreactive.
Step-by-step explanation:
The statement that the eight-element periodicity found in the Periodic Table is related to the number of electrons in the outermost energy level of the atoms that make up each element is false. The periodicity of elements in the periodic table is not based on an eight-element pattern, but rather on repeating trends in the properties of elements, which are a consequence of the number and distribution of valence electrons in their atoms. The periodic table is organized into groups and periods where elements with similar properties are in the same group, with valence electron configurations playing a key role in their reactivity.
For instance, Group 7 elements (also known as halogens) are very reactive because they have seven valence electrons and are just one electron short of having a full outer shell, which makes them keen to gain that one electron in reactions. On the other hand, Group 18 elements, known as noble gases, have full valence electron shells and are typically very unreactive. These trends in reactivity across different groups demonstrate the significance of valence electrons in determining chemical behavior rather than a simple eight-element periodic pattern.