Which of the following statement is correct?

Options

A. Elements of 3d and 4d-series are kept separately in periodic table.
B. Elements of 4f and 5f-series are kept separately in periodic table.
C. Elements of 5p and 6p-series are kept separately in periodic table.
D. All statements are correct.

Explanation

To determine which statement is correct regarding the placement of elements in the periodic table, we will analyze each of the provided statements step by step.

### Step-by-Step Solution:

1. **Understanding the Periodic Table Structure**:
- The periodic table is organized into periods (horizontal rows) and groups (vertical columns). Elements are categorized based on their electron configurations.

2. **Analyzing Statement A**:
- **Statement A**: "Elements of 3D and 4D series are kept separately in the periodic table."
- **Analysis**: The 3D series refers to the transition metals in the 4th period, and the 4D series refers to the transition metals in the 5th period. These elements are not kept separately; they are part of the main body of the periodic table. Therefore, this statement is **incorrect**.

3. **Analyzing Statement B**:
- **Statement B**: "Elements of 4F and 5F series are kept separately in the periodic table."
- **Analysis**: The 4F series includes the lanthanides, and the 5F series includes the actinides. Both of these series are indeed placed separately from the main body of the periodic table. Thus, this statement is **correct**.

4. **Analyzing Statement C**:
- **Statement C**: "Elements of 5P and 6P series are kept separately in the periodic table."
- **Analysis**: The 5P series and 6P series refer to the p-block elements in the 5th and 6th periods, respectively. These elements are part of the main body of the periodic table and are not kept separately. Therefore, this statement is **incorrect**.

5. **Analyzing Statement D**:
- **Statement D**: "All statements are correct."
- **Analysis**: Since we have determined that Statements A, C, and D are incorrect, this statement is also **incorrect**.

### Conclusion:
The only correct statement is **Statement B**: "Elements of 4F and 5F series are kept separately in the periodic table."

### Final Answer:
The correct option is **B**.

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