In the periodic table, which is described by the statement: each element has one more outer electron than the element before it?
a. a period
b. a family
c. a group
d. a vertical row

a is the answer to this question

explanation:

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.