The pair of elements showing diagonal relationship are:

Options

A. Li & Be
B. B & Be
C. Na & B
D. Li & Mg

Answer

To solve the question about the pair of elements showing a diagonal relationship, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Diagonal Relationship**:
- A diagonal relationship in the periodic table refers to the similarity in properties between certain pairs of elements that are diagonally adjacent to each other. This typically occurs between elements in the second and third periods.

2. **Identify the Relevant Periods**:
- The second period of the periodic table includes elements from Lithium (Li) to Neon (Ne).
- The third period includes elements from Sodium (Na) to Argon (Ar).

3. **Locate the Elements with Diagonal Relationships**:
- The elements that exhibit diagonal relationships are typically found in the second and third periods. The most commonly recognized pair is Lithium (Li) from the second period and Magnesium (Mg) from the third period.

4. **Check the Given Options**:
- Review the options provided in the question to identify which pair includes Lithium and Magnesium.

5. **Select the Correct Pair**:
- From the analysis, the only pair that shows a diagonal relationship is Lithium (Li) and Magnesium (Mg). Therefore, the correct answer is the pair of Lithium and Magnesium.

### Final Answer:
The pair of elements showing diagonal relationship are Lithium (Li) and Magnesium (Mg).

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