Which of the following is the formula of barium peroxide

BaO₂

The correct answer is option 4. BaO₂

Barium peroxide (\( \text{BaO}_2 \)) is a compound formed by the combination of barium (Ba) and oxygen (O). Here's an explanation:

1. Barium (Ba):

Barium is a chemical element with the symbol Ba and atomic number 56. It belongs to Group 2 (alkaline earth metals) in the periodic table.

2. Oxygen (O):

Oxygen is a chemical element with the symbol O and atomic number 8. It belongs to Group 16 (chalcogens) in the periodic table.

3. Formation of Barium Peroxide:
Barium peroxide is formed by the combination of one barium ion (Ba\(^{2+}\)) and two peroxide ions (\( \text{O}_2^{2-} \)). The peroxide ion (\( \text{O}_2^{2-} \)) consists of two oxygen atoms bonded together with a double bond, and it carries a charge of -2. The chemical equation for the formation of barium peroxide is:

\[ \text{Ba}^{2+} + \text{O}_2^{2-} \rightarrow \text{BaO}_2 \]

4. Structural Formula:

In the structure of barium peroxide, the barium ion is bonded to the peroxide ion. The peroxide ion has an oxygen-oxygen double bond. The structural formula can be represented as:

\[ \text{Ba}^{2+} - (\text{O}-\text{O}) - (\text{O}-\text{O}) \]

5. Uses:

Barium peroxide has applications as a bleaching agent and an oxidizing agent in various chemical processes.

In summary, the correct formula for barium peroxide is \( \text{BaO}_2 \), reflecting the combination of barium ions and peroxide ions in a specific ratio.