Structural and Mental Models - Essentials of Chemical Education - page 170

Fig. 6.15 Arrangement of C atoms in the graphite and diamond structure [ 19 ]

Table 6.2 Concrete models and mental models, their application and limits
Particle model of matter Interpretation: state of matter, change of state, kinetic theory

of gases, diffusion and solution processes, chemical
reaction without change of particles (e.g. formation
of alloys), etc. Limits: #

Mass-charge model (Dalton) Atom, atomic mass, element, compound, periodic table,

chemical reactions: regrouping of atoms and ions, law
of conservation of mass in chemical reactions, ions,
ionic symbols, ion lattice, undirected bond, molecule,
molecule symbol, molecule structure, directed bond,
empirical and structural formula, reaction equation, etc.
Limits: #

Nucleus and shell model
(Rutherford)

Nucleus, protons, neutrons, isotopes, radioactivity, atomic
shell, moving electrons, electron density, electron
clouds, electrolysis, metal-nonmetal-reaction, redox
reaction, electron transfer, etc. Limits: #

Nucleus and sub-shell model
(Bohr)

Ionic charge number, periodic table and octet rule, chemical
bond, ionic bond, covalent bond, hydrogen bond, etc.
Limits: #

Valence shell electron pair
repulsion model (VSEPR,
Gillespie)

Electron clouds, repulsion of electron clouds, bond angle,
bond length, spatial structure of molecules, etc. Limits: #

Atomic orbital model
(Schroedinger)

Orbital, hybridization, delocalization, structure of
the benzene molecule, calculation and prediction
of lattice or molecule structures, molecular design
with computers, etc.

solutions - from now atoms and ions should be called the basic particles of all
substances, and the ions may be added to Dalton's model. Following Rutherford's
discovery of the nucleus of atoms with his famous experiment in 1911, the
nucleus-shell model was created. Subsequently Bohr and Schroedinger described
and calculated the arrangement of electrons in sub-shells and orbitals.
Further functions of display and mental models: Models have not only the func-
tion to understand the structure of matter - there are other functions to understand
chemistry better.
Reduction of the learner's anthropomorphic conceptions . Preconceptions
like “sunbeams clear the puddle” or “acids eat up metals” have been described in
Chap. 1 “students' alternative conceptions.” These or similar comments can be