CHEMISTRY
JAMB 2007 - Question 32
Chemistry 2007 JAMB Past Questions - Question 32: The elements that belong to the third period of the periodic table are
Correct Answer
D
Explanation
* **Li, Be, Al, and P:** This set only includes 4 elements and misses several key elements from the third period like Na, Mg, S, Cl, and Ar.
* **Na, P, O, and Cl:** This set includes Na and Cl from the third period, but it has O which belongs to the second period and excludes Mg, Al, Si, and Ar from the third period.
* **B, C, N, and O:** This set only includes elements from the second period and completely misses all elements from the third period.
* **Na, Mg, S, and Ar:** This is the **correct** set. All these elements belong to the third period and cover it completely.
Therefore, only the last option, **Na, Mg, S, and Ar**, correctly identifies the elements belonging to the third period of the periodic table.

