Final answer:
A family in the periodic table refers to a vertical column where elements have similar properties. Each family or group is numbered from 1 to 18. A period in the periodic table refers to a horizontal row which represents the number of electron shells an atom of an element has.
Step-by-step explanation:
A family in the periodic table refers to a vertical column, also known as a group, where elements have similar properties. Each family or group is numbered from 1 to 18. For example, the alkali metals are part of Group 1, the alkaline earth metals are part of Group 2, the halogens are part of Group 7, and the noble gases are part of Group 8.
A period in the periodic table refers to a horizontal row. There are seven periods in the periodic table, labeled from 1 to 7. Each period represents the number of electron shells an atom of an element has. For example, elements in period 1 have one electron shell, elements in period 2 have two electron shells, and so on.