Which of the following process refers to ionisation potential ?

Options

A. `X_((s)) rarr X_((g))^(+) +e^(-)`
B. `X_((g)) +aq rarr X_((aq))^(+) +e^(-)`
C. `X_((g)) rarr X_((g))^(+) +e^(-)`
D. `X_((g)) +e^(-) rarr X_((g))^(-)`

Answer

To determine which process refers to ionization potential, we will follow these steps:

### Step 1: Understand the Definition of Ionization Potential
Ionization potential (or ionization energy) is defined as the minimum amount of energy required to remove the outermost electron from a neutral atom in the gaseous state.

**Hint:** Remember that ionization potential specifically refers to the energy needed to remove an electron from a neutral atom.

### Step 2: Write the General Equation for Ionization
We can represent the ionization process with a general equation. Let's assume our element is represented as AX (where A is the atom and X is an electron). The ionization process can be written as:
\[ \text{AX (g)} \rightarrow \text{A}^+ (g) + \text{e}^- \]
Here, AX is the neutral atom in the gaseous state, and upon losing an electron, it becomes a positively charged ion (A⁺) also in the gaseous state.

**Hint:** The equation shows that an electron is removed from the neutral atom, resulting in a positively charged ion.

### Step 3: Identify the Correct Option
Now, we need to match this equation with the provided options. The correct option will be the one that represents the process of removing an electron from a neutral atom in the gaseous state, resulting in a positively charged ion.

**Hint:** Look for an option that closely resembles the equation we derived.

### Conclusion
After analyzing the options, we find that the third option matches our derived equation, confirming that it correctly represents the process of ionization potential.

**Final Answer:** The third option refers to ionization potential.