Which of the following statements are correct regardly `17^(th)` group elements

Options

A. `I^(-)` reduces `Cu^(2+) ` to `Cu^(+)`
B. `Cl^(-)` reduces `Cu^(2+)` to `Cu^(+)`
C. `I_(3)^(-)`exists wheras `Cl_(3)^(-)` does not
D. The bond energy order is `Cl_(2) gt Br_(2) gt F_(2) gt I_(2)`

Explanation

To determine which statements are correct regarding the 17th group elements (the halogens: fluorine, chlorine, bromine, iodine, and astatine), we need to analyze the statements provided.

### Step-by-Step Solution:

1. **Identify the Halogens**:
The 17th group elements are known as halogens, which include fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).

2. **Evaluate the First Statement**:
The first statement mentions that Iodine (I) can reduce Cu²⁺ to Cu⁺.
- **Analysis**: Iodine can act as a reducing agent under certain conditions, and it can reduce Cu²⁺ to Cu⁺. This statement is generally correct.

3. **Evaluate the Second Statement**:
The second statement suggests that Iodine (I) and Bromine (Br) are very good reducing agents under rare conditions.
- **Analysis**: While bromine and iodine can act as reducing agents, they are not typically classified as "very good" reducing agents compared to other elements. This statement is somewhat misleading as it implies a stronger reducing ability than is commonly accepted.

4. **Conclusion**:
- The first statement is correct.
- The second statement is misleading and not generally accepted as correct.

### Final Answer:
- **Correct Statement**: The first statement regarding Iodine reducing Cu²⁺ to Cu⁺ is correct.
- **Incorrect Statement**: The second statement regarding Iodine and Bromine being very good reducing agents is misleading.