Q1(g). Formation of excited calcium atoms

Answer in brief

Nebulisation, desolvation, vaporisation, dissociation and excitation occur in sequence.

Key points

• Nebulisation forms solution droplets. Solvent evaporation leaves fine salt particles, which vaporise and undergo gas-phase dissociation/chemical reactions.
• The desired analytical species is ground-state neutral Ca(g), not intact dissolved CaCl₂.
• Collisions transfer thermal energy: Ca(g)+E→Ca*(g). Radiative relaxation gives Ca*→Ca+hν.
• Oxide formation and ionisation Ca ⇌ Ca⁺ + e⁻ compete and can lower the neutral-atom population. Flame composition and an ionisation buffer may be important.