Question

1. a horizontal row of elements in the periodic table is called a(n)

a. group.
b. family.
c. period.
d. octet.

Explanation:

Define periodic table rows

Horizontal rows are called periods, while vertical columns are called groups or families.

Identify the correct option

The question asks for a horizontal row, which corresponds to "period" (option c).

Answer:

• a. group.
• b. family.
• c. period. (Correct answer)
• d. octet.