Photoelectron imaging experiments for the negative ions, Pt and WC at a photon energy of 2.33 eV, are highlighted. In the Pt photoelectron angular distribution (PAD), intense signatures from the electron affinity (EA) transition (3)D3 < D-2(5/2), as well as several features from the excited states of Pt, D-2(3/2) and S-2(1/2), were observed. Present in the PAD of the valence isoelectronic diatomic molecule WC, are several transitions originating from the (2 Delta)(3/2) ground and higher energy (2 Delta)(5/2) and (4)Sigma excited states. Significantly, the spectroscopic transitions arising from WC exhibit similarities with those in Pt, providing insight into the reactivity of WC and Pt surfaces. Discussion regarding the photoelectron spectra of several other isoelectronic diatomic-elemental species further reveals quantitative aspects of the superatom concept. The recent surprising findings in this field are opening a new realm of studies pertaining to the behavior of matter governed by its unified atom/superatomic character. (C) 2010 Elsevier B. V. All rights reserved.