The H-O-H bond angles in `H_(3)O^(+)` are approximately `107^(@)`. The orbitals used by oxygen in these bonds are best described as :

Options

A. p-orbitals
B. sp-hybrid orbitals
C. `sp^(2)`-hybrid orbital
D. `sp^(3)`-hybrid orbital

Explanation

To determine the orbitals used by oxygen in the bonds of the hydronium ion (H₃O⁺), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structure of H₃O⁺**:
- The hydronium ion (H₃O⁺) is formed when a water molecule (H₂O) reacts with a proton (H⁺). In H₂O, oxygen has two lone pairs and forms two bonds with hydrogen atoms. When H⁺ is added, it forms a coordinate bond with one of the lone pairs on oxygen.

2. **Draw the Lewis Structure**:
- The Lewis structure of H₃O⁺ shows oxygen at the center with three hydrogen atoms bonded to it and one lone pair of electrons remaining on oxygen.

3. **Determine the Steric Number**:
- The steric number is calculated by adding the number of sigma bonds and lone pairs. In H₃O⁺, there are three sigma bonds (one for each H) and one lone pair on oxygen.
- Steric Number = Number of Sigma Bonds + Number of Lone Pairs = 3 + 1 = 4.

4. **Determine the Hybridization**:
- The hybridization corresponding to a steric number of 4 is sp³. This means one s orbital and three p orbitals from oxygen mix to form four equivalent hybrid orbitals.

5. **Conclusion**:
- The orbitals used by oxygen in the H-O-H bonds of H₃O⁺ are best described as sp³ hybridized orbitals.

### Final Answer:
The orbitals used by oxygen in the bonds of H₃O⁺ are best described as **sp³ hybridized orbitals**.

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