Final answer:
Elements in the same group (vertical columns) on the periodic table have similar chemical properties due to having the same valence electron configuration. Families such as alkali metals and noble gases demonstrate consistent behaviors within their respective groups, and moving down a group can increase the element's metallic character.
Step-by-step explanation:
Noticing the location of elements in each family on the periodic table, we see that elements with similar chemical properties are grouped together in vertical columns called groups or families. These groups are numbered 1 to 18. Each element within a group has a similar number and distribution of valence electrons, which accounts for their similarities in chemical behavior.
For example, alkali metals in Group 1 have one valence electron making them highly reactive, while noble gases in Group 18 have a full valence shell and are very nonreactive.
Additionally, moving down a group typically increases an element's metallic character; for instance, oxygen (at the top of Group 16) is a nonmetallic gas, while polonium (toward the bottom) is a metallic solid.