What is a family of elements?

• A. Elements with similar properties
• B. Elements that are metals
• C. Elements with equal mass
• D. Elements found in the same period

Answer: (A)

A family of elements refers to a column in the periodic table where the elements share similar properties because they have the same number of valence electrons in their outermost shell. That shared electron configuration drives their chemical behavior, so elements in the same family tend to react in comparable ways and show similar trends as you move down the column. For example, alkali metals are all highly reactive metals, halogens are highly reactive nonmetals, and noble gases are generally inert. This idea focuses on how the arrangement of electrons shapes chemistry, not on whether an element is a metal, its mass, or which row it sits in. Being in the same period would group elements by row, which doesn’t define a family.