Which of the following species is amphoteric in nature ?

Options

A. `H_3O^+`
B. `Cl^-`
C. `HSO_4^-`
D. `CO_3^(2-)`

Explanation

To determine which species is amphoteric in nature, we need to understand the definition of amphoteric substances. Amphoteric substances can act as both acids and bases. Let's analyze the given options step by step.

### Step-by-Step Solution:

1. **Understanding Amphoteric Nature**:
- An amphoteric substance can donate a proton (H⁺) like an acid and can also accept a proton like a base.

2. **Evaluating Each Option**:
- **Option A: H₃O⁺ (Hydronium ion)**:
- This species can donate a proton (acting as an acid) but cannot accept a proton. Therefore, it is not amphoteric.

- **Option B: Cl⁻ (Chloride ion)**:
- This species can accept a proton (acting as a base) but cannot donate a proton. Therefore, it is not amphoteric.

- **Option C: HCO₃⁻ (Bicarbonate ion)**:
- This species can accept a proton to form H₂CO₃ (carbonic acid) or donate a proton to form CO₃²⁻ (carbonate ion). Thus, it can act as both an acid and a base, making it amphoteric.

- **Option D: HSO₄⁻ (Hydrogen sulfate ion)**:
- This species can donate a proton to form SO₄²⁻ (sulfate ion) or accept a proton to form H₂SO₄ (sulfuric acid). Thus, it can also act as both an acid and a base, making it amphoteric.

3. **Conclusion**:
- Both HCO₃⁻ and HSO₄⁻ are amphoteric. However, if the question asks for a single species, HSO₄⁻ is typically recognized as a classic example of an amphoteric species.

### Final Answer:
The amphoteric species among the given options is **HSO₄⁻ (Hydrogen sulfate ion)**.