AbstractElectronically excited tin atoms Sn(51D2), 1.068 eV above the 53P0ground state, have been generated by the pulsed irradiation of tin tetramethyl and monitored photoelectrically in absorption by time‐resolved attenuation of atomic resonance radiation at λ=285.06 nm [Sn((5d3F20) ← (5p21D2))]. Deactivation rate constants are reported for the quenching of Sn(51D2) with a range of collision partners and the resulting data are compared with those for analogous states within group IV, namely, C(21D2) and Pb(61D2). The data are discussed in terms of correlations based on both the weak and strong spin orbit coupling approximat