Which of the following statements is most applicable to hydrogen ?

Options

A. It can act as a reducing agent only
B. It can act as an oxidising agent only
C. It can act as both as oxidising and reducing agents
D. It can act neither as an oxidising nor as a reducing agent.

Explanation

To determine which statement is most applicable to hydrogen, we need to analyze each of the provided statements about its chemical behavior.

### Step-by-Step Solution:

1. **Evaluate the First Statement**:
- The first statement claims that hydrogen can act as a reducing agent only.
- **Analysis**: Hydrogen can indeed act as a reducing agent, but it can also act as an oxidizing agent. For example, when hydrogen reacts with sodium, it forms sodium hydride (NaH) and causes sodium to lose an electron (oxidation), indicating that hydrogen acts as an oxidizing agent in this reaction. Therefore, this statement is incorrect.

2. **Evaluate the Second Statement**:
- The second statement claims that hydrogen can act as an oxidizing agent only.
- **Analysis**: Similar to the first statement, while hydrogen can act as an oxidizing agent, it can also act as a reducing agent. For instance, in the reaction with lead(II) oxide (PbO), hydrogen reduces PbO to lead (Pb), indicating that hydrogen is acting as a reducing agent. Thus, this statement is also incorrect.

3. **Evaluate the Third Statement**:
- The third statement claims that hydrogen can act as both an oxidizing and a reducing agent.
- **Analysis**: This statement is correct. As discussed, hydrogen can act as an oxidizing agent in reactions such as with sodium and as a reducing agent in reactions such as with lead(II) oxide. Therefore, this statement is valid.

4. **Evaluate the Fourth Statement**:
- The fourth statement claims that hydrogen can act neither as an oxidizing nor as a reducing agent.
- **Analysis**: This statement is incorrect because we have established that hydrogen can indeed act as both an oxidizing and reducing agent.

### Conclusion:
After evaluating all the statements, the correct answer is that hydrogen can act as both an oxidizing and reducing agent (Statement 3).

### Final Answer:
The most applicable statement to hydrogen is: **It can act as both an oxidizing and reducing agent.**