Define a family in terms of the periodic table

Family, the column (up and down rows) each column is a family.

In chemistry, a family is a group of elements with similar chemical properties. Chemical families tend to be associated with the vertical columns on the periodic table. The term "family" is synonymous with the term "group". Because the two words have defined different sets of elements over the years, the IUPAC recommends the numerical system numbering elements from group 1 to group 18 be used over the common names of families or groups.

Explanation:

maybe not to sure