Short Answer Q&A – d- and f-block Elements (NCERT Class 12 Chemistry) Q: What are transition elements? A: Elements whose atoms or ions (in a stable oxidation state) contain partially filled d -orbitals. Q: Give the general outer electronic configuration of d-block elements. A: ( n -1) d 1–10 ns 1–2 . Q: Why are Zn, Cd, and Hg not considered true transition elements? A: They have completely filled d-orbitals ( d 10 ) in both atomic and common oxidation states (+2). Q: Why is Ag considered a transition element? A: It exhibits the +2 oxidation state (Ag 2+ ), with partially filled 4d 9 configuration. Q: Write the electronic configuration of Cr (Z=24). A: [Ar] 3d 5 4s 1 (Half-filled stability). Q: Write the electronic configuration of Cu (Z=29). A: [Ar] 3d 10 4s 1 (Fully-filled stability)...

Basic Concepts 1.Q:What is a coordination compound ?      A:A compound containing a central metal atom/ion bonded to ligands via coordinate bonds . 2. Q: What is a ligand ?      A: An ion or molecule that donates a lone pair of electrons to the central metal atom/ion. 3. Q:What is coordination number ?      A:The number of ligand donor atoms directly bonded to the central metal ion. 4. Q:What are monodentate ligands ?      A:Ligands that donate only one pair of electrons (e.g., NH₃, H₂O, Cl⁻). 5. Q:Give an example of a polydentate ligand .      A: Ethylenediamine (en), Oxalate (C₂O₄²⁻). 6. Q:What is a chelating ligand ?      A: A ligand that forms two or more coordinate bonds with the same central metal ion. 7. Q:What is the oxidation number of Co in [Co(NH₃)₆]Cl₃?      A: +3. 8. Q:What is the difference between inner and outer orbital complexes?...

 

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