2020/01/08 by Kasper P. Kepp · 1 citation
Chemistry · Social Sciences · #Analytical chemistry methods development #Radioactive element chemistry and processing #Forensic Fingerprint Detection Methods
paper · pdf · doi:10.1002/cphc.202000013
openalex publication_date 2020/01/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Humans have appreciated the "noble" metals for millennia, yet modern chemistry still struggles with different definitions. Herein, metal nobleness is analyzed using thermochemical cycles including the different bulk, gas, and solution states implied by these definitions. The analysis suggests that metal nobleness mainly reflects inability to fulfil the electron demands of electronegative oxygen. Accordingly, gold is the most noble metal in existence, not because of d-band properties of the solid state, but because gold's electronegativity is closest to that of oxygen, producing weaker polar covalent bonding. The high electronegativity arises from the effective nuclear charge due to diffuse d-states, enforced by relativistic effects. This explanation accounts for the activity series, corrosion tendency, and trends in oxygen chemisorption, which other models do not. While gold is the most noble metal, the ranking of Ag, Pt, and Pd depends on the thermochemistry as discussed in detail.