Analysis of the mental model about the atom concept in Spanish 15- to 18- years old students

The present research investigates the mental models about the atom of Spanish 15- to 18- years old students. A sample of 454 students was taken into account within a representative Spanish context. A specific questionnaire, validated before students solved it, where the students should draw, define and argue was designed. It has been found that most of the students understand the atom as a mix of several models. In general, the models they mix are those that they studied during their last educational course. Some students possess a unique mental model about the atom (Bohr´s model), and a really few students described the atom as it could be expected according to their educational level. Several reasons have been appointed among them are: i) the construction of a mental model is a hard and slow process, even more in the case of the atom, ii) this is a complex concept which requires abstraction and to use spatial knowledge in very young students, and iii) teachers offer to students few situations to check their mental models, and thus, it takes so much time to find the strengths and weaknesses of their models.