Final answer:
(Option B) is correct answer. Na2SO4 contains three different elements: Sodium (Na), Sulfur (S), and Oxygen (O), making three the correct answer.
Step-by-step explanation:
The compound Na2SO4 consists of three different elements. These are:
- Sodium (Na)
- Sulfur (S)
- Oxygen (O)
There are two atoms of sodium, one atom of sulfur, and four atoms of oxygen in one formula unit of sodium sulfate. Hence, the correct answer to how many elements are present in the compound Na2SO4 is three (Option B).