Which set contains pair of elements that do not belong to same group but show chemical resemblance ?

Options

A. `Hf,Zr`
B. `K,Rb`
C. `Be,Al`
D. `B,Al`

Explanation

To solve the question of which set contains pairs of elements that do not belong to the same group but show chemical resemblance, we will follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Diagonal Relationship**:
- Diagonal relationships occur in the periodic table where certain elements in different groups but in adjacent periods exhibit similar properties. This is particularly observed in the s-block and p-block elements.

2. **Identify the Elements in the Options**:
- We need to analyze the sets provided in the options. The elements to consider are:
- Lithium (Li), Beryllium (Be), Boron (B), Carbon (C)
- Sodium (Na), Magnesium (Mg), Aluminium (Al), Silicon (Si)

3. **Check Group and Period of Each Element**:
- Lithium (Li) - Group 1, Period 2
- Sodium (Na) - Group 1, Period 3
- Beryllium (Be) - Group 2, Period 2
- Magnesium (Mg) - Group 2, Period 3
- Boron (B) - Group 13, Period 2
- Aluminium (Al) - Group 13, Period 3
- Carbon (C) - Group 14, Period 2
- Silicon (Si) - Group 14, Period 3

4. **Identify Pairs that Show Chemical Resemblance**:
- From the above elements, we can see that:
- Lithium (Li) and Magnesium (Mg) show similar properties.
- Beryllium (Be) and Aluminium (Al) also show similar properties.
- Boron (B) and Silicon (Si) show similar properties.

5. **Select the Correct Pair**:
- The pair that does not belong to the same group but shows chemical resemblance is:
- Lithium (Li) and Magnesium (Mg) (different groups but similar properties).
- Beryllium (Be) and Aluminium (Al) (same group).
- Boron (B) and Silicon (Si) (same group).
- Therefore, the correct answer is Lithium (Li) and Magnesium (Mg) or Boron (B) and Silicon (Si) as they show diagonal relationships.

6. **Final Answer**:
- The correct set that contains pairs of elements that do not belong to the same group but show chemical resemblance is **Lithium (Li) and Magnesium (Mg)**.