Multiple chemistry education research studies at the secondary level have characterized students' difficulties regarding a conceptual understanding of the quantum model of the atom. This research explores undergraduate students' interpretations of multiple representations of the atom. Semistructured interviews were conducted with first-year university chemistry students (n = 26) and second-semester physical chemistry students (n = 8) after they were taught and tested on the quantum model of the atom in their respective courses. During the interview, students were asked to interpret four representations of the atom (an electron cloud model, a probability representation, a boundary surface representation, and the Bohr model) and to rank each of the representations from most preferred to the least preferred. Nearly two-thirds of the students ranked the electron cloud and Bohr-model as their two most preferred representations. Students invoked ideas from classical mechanics to interpret the electron cloud model and used probabilistic language to describe the Bohr model of the atom.