Answer: 4.
- A 0
- B 2
- C 1
- D 4
Correct answer: D. 4
Explanation: Co<sup>3+</sup> is d<sup>6</sup>; F<sup>-</sup> is a weak field ligand, so it is high spin t<sub>2g</sub><sup>4</sup>e<sub>g</sub><sup>2</sup> with 4 unpaired electrons (unlike low-spin [Co(NH<sub>3</sub>)<sub>6</sub>]<sup>3+</sup>).
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.