What is true about the groups in the periodic table?

The correct choice highlights that elements within the same group of the periodic table exhibit similar chemical properties. This similarity arises because elements in a group have the same number of electrons in their outermost shell, known as valence electrons. This characteristic largely dictates how the elements interact chemically with other substances.

For instance, alkali metals such as lithium, sodium, and potassium belong to Group 1 and are highly reactive, typically reacting vigorously with water in similar ways. Likewise, the halogens in Group 17, including fluorine, chlorine, and bromine, exhibit similarities in their reactivity and form diatomic molecules (like F2 and Cl2) when existing as gases.

This shared outer electron configuration leads to comparable bonding behavior and reactivity patterns across the group, making it a defining characteristic of how similar the chemical properties are.

While there are groups with elements exhibiting similar physical properties, such as color or phase at room temperature, these properties are not exclusively confined to groups and can vary widely even among elements within the same group. Furthermore, the idea that nuclear properties vary widely within groups is misleading, as nuclear properties are more closely related to the specific elements’ isotopes and not to their group positioning in the periodic table. Thus, the assertion that