In teaching sciences, models are often used to introduce, elaborate or simplify real-world phenomena or concepts. It is, however, often the case that misconceptions arise from or are facilitated by these teaching models during their transition to mental models of the individual learners. For instance, models are often seen as direct replicas of something real--scaled versions of reality. Even though for architectural models, this approach is sufficient, in physics, other model types must also be taken into account. In particular, in quantum physics, the ability for abstract model building is essential. In our exploratory study with 3108 participants, the dispositions towards models in physics in general and models of the atomic hull in particular were analysed. Based on this quantitative data, two independent dimensions of the participants' mental models were extracted: (i) Functional Fidelity and (ii) Fidelity of Gestalt. Based on these empirical findings, four main types of mental models are proposed.