Final answer:
Elements with similar chemical properties are grouped together in the periodic table into groups or families based on their element class, group number, and state of matter at room temperature.
Step-by-step explanation:
In the periodic table, elements with similar chemical properties are grouped into columns called groups or families. These groups have names, such as alkali metals, alkaline earth metals, halogens, and noble gases. For each pair of elements, three things they have in common can include being in the same group (or family), belonging to the same element class, and existing in the same state of matter at room temperature.