Oxygen molecule is

Options

A. one axial s-s overlap and one p-p axial overlap
B. two p-p axial overlaps
C. two p-p sidewise overlaps
D. one p-p axial and one p-p sidewise overlap.

Explanation

To determine the bonding in an oxygen molecule (O₂), we need to analyze the electronic configuration and the types of overlaps that occur between the two oxygen atoms. Here’s a step-by-step solution:

### Step 1: Understand the Electronic Configuration of Oxygen
Oxygen has an atomic number of 8, which means it has 8 electrons. The electronic configuration is:
- 1s² 2s² 2p⁴

This indicates that:
- The 1s subshell has 2 electrons.
- The 2s subshell has 2 electrons.
- The 2p subshell has 4 electrons, which can be distributed as follows:
- 2 electrons in the px orbital (2 in one direction)
- 1 electron in the py orbital (1 in another direction)
- 1 electron in the pz orbital (1 in a third direction)

### Step 2: Determine the Bonding in O₂
In an O₂ molecule, the two oxygen atoms are bonded by a double bond. A double bond consists of one sigma (σ) bond and one pi (π) bond.

### Step 3: Identify the Types of Overlaps
1. **Sigma Bond Formation**:
- The sigma bond in O₂ is formed by the axial overlap of the p orbitals. Specifically, the pz orbitals from each oxygen atom overlap end-to-end (axial overlap) to form the σ bond.

2. **Pi Bond Formation**:
- The pi bond is formed by the sidewise overlap of the py orbitals from each oxygen atom. This sidewise overlap creates the π bond.

### Step 4: Analyze the Options
Now, let's evaluate the options provided in the question:
1. **Option 1**: 1 axial SS overlap and 1 PP axial overlap - Incorrect, as the 2s orbital does not participate in bonding.
2. **Option 2**: 2 PP axial overlaps - Incorrect, as only one axial overlap occurs (the σ bond).
3. **Option 3**: 2 PP sidewise overlaps - Incorrect, as only one sidewise overlap occurs (the π bond).
4. **Option 4**: 1 PP axial and 1 PP sidewise overlap - Correct, as this accurately describes the bonding in O₂.

### Conclusion
The correct answer is **Option 4: 1 PP axial and 1 PP sidewise overlap**.

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