(No abstract - this is the first paragraphs of the article.)
The fragmentary system of the Italian secondary school system means that pupils may receive their first chemistry course anytime between the ages of 14-17 years(1). These courses may be of quite different length, but a common feature is the introduction of the orbital concept of atomic and molecular structure. While such an approach makes it possible to deduce and rationalize a large amount of chemical knowledge, there is a groing realization that this is possibly not the best way to introcue pupils to chemistry.
First chemistry courses are often taught by graduates in biological or geological sciences who may not have a full understanding of atomic and molecular structure. They are using a variety of textbooks whose presentation of these topics often leaves much to be desired.
In the 1979/80 academic year we made a small-scale study to gain some idea of the level of chemical knowledge achieved by pupils at the end of their high school courses. For this purpose we submitted a list of 20 questions to first-year students in the Faculry of Sciences at the University of Bologna.
The question that obtained the smallest number of abstentions and largest number of incorrect answers was "What is an atomic orbital?" This fact lead us to analyze the answers to this question in detail.