Question

which letter represents one of the elements in period 4?
a
b
c
d

Explanation:

Step1: Recall the definition of a period in the periodic table

In the periodic table, a period is a horizontal row.

Step2: Analyze each option

• Option A: The element labeled A is in a separate row (the lanthanide series, which is a special case of Period 6).
• Option B: The element labeled B is in Period 4.
• Option C: The element labeled C is in Period 5.
• Option D: The element labeled D is in Period 2.

Answer:

B