Answer
The periodic table has seven periods.
For period 3, we have the following eight elements:
Sodium (Na)
Magnesium (Mg)
Aluminum (Al)
Silicon (Si)
Phosphorus (P)
Sulfur (S)
Chlorine (Cl)
Argon (Ar)
Work Step by Step
For this problem, we need to look at the periodic table on the inside cover of our book.
The periods are labeled 1 through 7; therefore, we have seven periods.
For period 3, we have the following eight elements:
Sodium (Na)
Magnesium (Mg)
Aluminum (Al)
Silicon (Si)
Phosphorus (P)
Sulfur (S)
Chlorine (Cl)
Argon (Ar)
