Answer: +3.
- A +3
- B +2
- C +1
- D 0
Correct answer: A. +3
Explanation: NH<sub>3</sub> = 0, Cl = -1, overall charge = +2. Let Co = x: x + 5(0) + (-1) = +2; x = +3.
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.