The concept of chemical change is a fundamental pivot of the teaching of chemistry. If this course does not help
students build the basic concepts, it would be difficult to achieve the desired results and students are not able to
identify the chemical reactions of other phenomena such as the physical transformation of matter, for example (El
Hassane TOULI and al., 2011).
Modeling the chemical transformation is discussed in the Moroccan side from the class of core science and
technology.
To evaluate the performances of students at this level of modeling the chemical transformation, we have submitted
to a diagnostic questionnaire.
It is clear that most of the difficulties experienced by students in the teaching of chemistry are generated by noncollection
of logical links between different parts of a documentary or experimental activity. The result is a poor
student understanding of what is expected of them.