From observations to descriptions to explanations From observations to descriptions to explanations M.C.Capizzo, L. Lupo and R.M. Sperandeo-Mineo Dipartimento di Fisica e Tecnologie Relative, Università di Palermo, Italy properties and behaviours of gases

OBJECTIVE: To provide student-teachers with learning environments and computational tools that will help them to express and reflect on their concepts and ideas about phenomena and support their activities concerning exploration, experimenting and modelling

 Hands-on learning through activities : experiments and software  Training connected with experimentation in classroom

Teachers by themselves have to experience the kind of learning we think they should provide to the students

Physics Models as  Explanations of phenomena:  Descriptions of phenomena: *

The approach is developed in several phases  observing  analysing pupil’s spontaneous representations  experimenting  modelling

OBSERVING Motion of motes Heating of compressed gasses Diffusion of perfume vapours Thermal expansion of gasses

Boyle’s law (P vs V) A commercial sensor of pressure is used and volume is registered by the operator. fitting is performed using EXCEL EXPERIMENTING (USING MBL)

I Gay Lussac law (V vs T) I Gay Lussac law (V vs T) Sensors of temperature and motion are used.. Fitting is performed using Excel. Experimental data (Pasco system)

EXPERIMENTING (USING MBL) II Gay Lussac Law (P vs T) Sensors of temperature and pressure are used. Experimental data (Pasco system)

Pupil relevant ideas of atomic-scale models Gas molecules maintain some macroscopic properties (like thermal expansion, elasticity, stiffness,…) Gas molecules can move, on the contrary of liquid and solid molecules Gas molecules naturally tend to go away each other Gas molecules are embedded in some kind of substance (sometime called “heat”)

MODELLING USING “INTERACTIVE PHYSICS”

Introducing the pressure concept from a microscopic point of view

Experimenting with models THE MODEL: N particle (hard spheres) M (mass) = mean mass of air molecules v i (velocities) equal in modulo and random directions V (volume of the container)= m 3

Video display of the Applet Speed, number of particles and volume can be chosen by the user.

Results of simulations

 Computer–based learning environments can create contexts in which student-teachers can be actively engaged in their learning processes;  The different channels conveying information allow the using of different learning strategies;

A new curriculum to process-based from content-based

Learning by doing and by reflecting on the procedures originating the results