Final answer:
Elements in the same family of the periodic table have similar chemical properties due to their shared number of valence electrons, allowing for the replacement of one element with another of the same family.
Step-by-step explanation:
In chemistry, elements in the same family or group in the periodic table have similar chemical properties. This is because they have the same number of valence electrons, which determines how they will react with other elements. For example, the elements in Group 1A, also known as the alkali metals, all have one valence electron and react in similar ways. So, it is possible to replace one element from a family with another of the same family because they have similar chemical properties.