Answer: 6.
- A 6
- B 3
- C 4
- D 2
Correct answer: A. 6
Explanation: Coordination number = number of ligand donor atoms directly bonded to the metal. 6 NH<sub>3</sub> ligands give CN = 6.
The three common coordination geometries: octahedral (6 ligands), tetrahedral (4 ligands), and square planar (4 ligands in one plane).
Concept context
Study of compounds where a central metal atom is bonded to surrounding ligands. Covers nomenclature, types of isomerism, bonding theories (VBT, CFT), and applications in medicine, photography, and industry.