The reaction given below shows an atom of element X being changed into an ion `:`
`underset("Element")(X) rarr underset("Ion")(X^(+))`
Consider the following statements.
I. One electron is lost.
II. The ion is cation.
III. The ion is smaller than the atom.
Identify the correct option.

Options

A. I only
B. I and II only
C. II and III only
D. I,II and III

Answer

To solve the problem, we need to analyze the transformation of element X into its ion, X⁺, and evaluate the given statements.

### Step-by-Step Solution:

1. **Understanding the Reaction**:
- The reaction shows the conversion of element X into its ion X⁺. This indicates that element X is losing an electron.

2. **Analyzing Statement I**:
- **Statement I**: "One electron is lost."
- When X loses one electron to become X⁺, it indeed loses one electron. Therefore, this statement is **true**.

3. **Analyzing Statement II**:
- **Statement II**: "The ion is a cation."
- A cation is defined as a positively charged ion. Since X⁺ has a positive charge, it is classified as a cation. Thus, this statement is also **true**.

4. **Analyzing Statement III**:
- **Statement III**: "The ion is smaller than the atom."
- When an atom loses an electron, the remaining electrons are held more tightly by the nucleus due to the increased effective nuclear charge (more protons than electrons). This results in a smaller ionic radius for the cation compared to the neutral atom. Therefore, this statement is **true** as well.

5. **Conclusion**:
- All three statements (I, II, and III) are correct.

### Final Answer:
All statements are correct.