Predict correct statement.

Options

A. `E_(ea) gt 0 (E_(ea) `= Electron affinity) implies that electron attachment is exothermic
B. Electron gain enthalpy of `O^-` ion is negative
C. The electron gain enthalpy of a species X is the negative of the ionization enthalpy is of its negative ion
D. Both (1) & (3)

Answer

To solve the question "Predict the correct statement," we need to analyze the given statements regarding electron affinity and electron gain enthalpy.

### Step-by-step Solution:

1. **Understanding Electron Affinity**:
- Electron affinity is defined as the amount of energy released when an electron is added to a neutral atom in the gas phase.
- If the electron affinity is greater than zero, it means that energy is released when the atom gains an electron, indicating that the process is exothermic.

**Hint**: Remember that exothermic processes release energy, which is typically indicated by a negative change in enthalpy (ΔH < 0).

2. **Analyzing Statement 1**:
- The first statement claims that "electron affinity greater than zero implies that electron attachment is exothermic."
- Since we established that a positive electron affinity indicates energy release, this statement is correct.

**Hint**: Think about the relationship between energy release and the sign of electron affinity.

3. **Understanding Electron Gain Enthalpy**:
- Electron gain enthalpy is the energy change when an electron is added to a neutral atom to form an anion.
- For anions, the electron gain enthalpy is typically negative because energy is released when an electron is added.

**Hint**: Keep in mind that the sign of electron gain enthalpy can indicate whether the process is favorable or not.

4. **Analyzing Statement 3**:
- The third statement mentions that "the electron gain enthalpy of O⁻ ion is negative."
- Since adding an electron to oxygen (O) to form O⁻ releases energy, this statement is also correct.

**Hint**: Consider how the formation of anions typically involves energy release.

5. **Comparing Electron Gain Enthalpy and Ionization Energy**:
- The video mentions that the electron gain enthalpy of an atom (X) is the negative of the ionization energy of its negative ion (X⁻).
- This is true because to remove an electron from X⁻ (which is negatively charged), energy must be supplied, thus linking the two concepts.

**Hint**: Recall that the ionization energy is the energy required to remove an electron, which is opposite in sign to the energy released when gaining an electron.

6. **Conclusion**:
- Since both statements 1 and 3 are correct, the final answer is that option 4 is correct, which states that both statements 1 and 3 are true.

### Final Answer:
The correct answer is option 4: Both statements 1 and 3 are correct.