AFOQT Practice Test

How are groups in the periodic table related to elements' outer electron arrangements?

1. Elements in a group have the same number of protons

2. Elements in a group have different outer electron arrangements

3. Elements in a group share the same outer electron arrangement

4. Elements in a group have the same number of neutron shells

The correct answer is: Elements in a group share the same outer electron arrangement

The correct choice indicates that elements in a group share the same outer electron arrangement. In the periodic table, a group, or family of elements, consists of elements that have similar chemical properties due to having the same number of electrons in their outermost shell, also known as valence electrons. This similarity in the outer electron configuration directly influences how these elements bond and react with others. For instance, elements in the alkali metals group all have one electron in their outer shell, making them highly reactive and sharing similar properties. The other options provided do not accurately reflect how groups in the periodic table relate to their outer electron arrangements. Elements in a group do not have the same number of protons, which defines their identity; they can have varying atomic numbers. The claim that elements in a group have different outer electron arrangements contradicts the defining property of groups in the periodic table. Lastly, the idea that elements in a group have the same number of neutron shells is not applicable, as the term "neutron shells" is not conventionally used in discussing periodic table groups. Rather, it's the arrangement of electrons in the outer shell that matters.