Explain the significance of the ‘spin-only’ formula in determining magnetic moments, and how does the experimental data for some first-row transition metal ions support this calculation?

The ‘spin-only’ formula (μ = √(n(n+2)), where n is the number of unpaired electrons) is significant for quickly estimating magnetic moments by considering only electron spin contributions, excluding orbital effects. Experimental data for first-row transition metal ions often supports this calculation, particularly in high-spin configurations where electrons preferentially occupy degenerate orbitals. The agreement between calculated and experimental magnetic moments suggests that, in many cases, the spin contribution dominates the magnetic behavior of these compounds. While it provides a simplified approach, the ‘spin-only’ formula offers valuable insights into the magnetic properties of transition metal complexes with unpaired electrons.