Atomic orbitals are affected by external perturbations, such as the proximity of other atoms or exposure to electric or magnetic fields, that induce Stark and Zeemann splittings. The thought experiment: What would happen with these orbitals if one would position a fraction of a positive elementary charge with a tweezer at about half the atomic radius? This would allow for a highly controlled experiment on the alteration of atomic orbitals by a perturbation. Such a tweezer does not exist, so this remains a thought experiment. However, we can achieve something similar in an artificial 2D atom such as a quantum corral where we put single adsorbate atoms inside, which can be engineered by lateral manipulation with scanning probe microscopy. We show that the perturbation potential qualitatively follows the one between two natural atoms, a long-range attraction followed by a short-range repulsion. We demonstrate the state-selectivity of the short-range interaction leading to tunable electronic states. Surprisingly, long-range Coulomb attraction can be detected experimentally, even though charges are strongly screened on the metal surface. We estimate an effective charge of the adsorbate on the order of 1/1000 of an elementary charge. The perturbed orbital is imaged by atomic force microscopy and scanning tunneling microscopy and described by perturbation theory. As a practical application, this introduces the ability to tune the geometry of the reactivity of an artificial atom, similar to the change in the chemical reactivity of a natural atom, when it is bound to other atoms.