It seems you're looking for a comprehensive revision of D and F Block Elements in Chemistry, particularly for Class 12 with a focus on JEE, NEET, and board exams. Here’s a concise overview of the key points to cover:

1. Overview of D Block and F Block Elements

• D Block Elements: Transition metals found in groups 3-12 of the periodic table.
• F Block Elements: Lanthanides and actinides, which are placed separately at the bottom of the periodic table.

2. Electronic Configuration

• D Block Elements: General electronic configuration is $[noble\ gas] \, (n-1)d^1-10 \, ns^0-2$.
• F Block Elements: General electronic configuration is $[noble\ gas] \, (n-2)f^1-14 \, (n-1)d^0-1 \, ns^2$.

3. Properties of D Block Elements

• Variable Oxidation States: Transition metals exhibit multiple oxidation states due to the involvement of d-electrons.
• Catalytic Activity: Many d-block elements act as catalysts in various chemical reactions.
• Formation of Colored Ions: The presence of unpaired d-electrons gives rise to characteristic colors in compounds.

4. Properties of F Block Elements

• Lanthanides: Typically show +3 oxidation state, exhibit similar chemical properties, and are used in making strong magnets.
• Actinides: Radioactive elements that can show +3, +4, +5, or +6 oxidation states, known for complexity in behavior.

5. Applications of D and F Block Elements

• Industry and Technology: Used in manufacturing, alloys, batteries, and electronic devices.
• In Medicine: Certain d and f block elements are used in diagnostic imaging.

6. Important Compounds and Reactions

• Study key compounds formed by d and f block elements, such as:
  • Coordination compounds
  • Complex ion formation
  • Oxidation-reduction reactions

7. Common Questions and Exam Focus

• Be prepared for questions regarding:
  • Properties and trends in the periodic table
  • Comparison of d and f block elements
  • Specific applications and reactions of certain elements.

Conclusion

Focus your revision on these core concepts, properties, and applications. Practice previous year questions related to D and F Block elements, and ensure a good understanding of their behavior in chemical reactions.

Good luck with your revision!