Chemistry Reference
In-Depth Information
unit cell concerning the sodium chloride structure. Wirbs [
16
] has introduced those
sphere packings and unit cells into chemistry lectures in grade 8 and 9 for deriving
formulae from chemical structures - and she could prove that students with little
knowledge in fraction calculation are able to add all parts of spheres of the unit cell
to find the ratio formula (see Fig.
4.4
). On this way, they must apply their spatial
ability.
From psychologists, we know that “Space” is a primary factor of intelligence.
Bloom stated that “at the age of nine only 50% and at the age of 14 about 80% of the
parameter Space have developed” [
17
]. On this base, a spatial ability test
concerning chemical structures was created with the aim to know from which age
spatial ability is sufficient to work with two-dimensional pictures of structural
models and to interpret them in the three-dimensional way. Five of those questions
are represented (see Fig.
4.5
).
The results show that in grade 7, the 13-14-year-old students have very different
abilities to solve those questions: “Testing the correlation between performance in
intelligence and spatial ability the data show that a sufficient correlation does not
exist for seventh graders. Conversely, all correlation coefficients in grades 8 and 9
appear to be significantly different from zero. It is striking that on the average the
girls' correlation coefficients show a weaker correlation than the boys. In the case of
a great number of seventh-grade students, spatial ability has not developed suffi-
ciently compared with general intelligence, so that teachers should avoid those
problems that require the application of spatial ability.” [
18
]
Like other empirical research of psychologists shows, the boys have performed
better than the girls: boys may have a better training of spatial ability by their
technical toys than the girls. Temechegn [
19
] compared results of space tests in
Germany and his native land Ethiopia. He found out that for private schools, the
same result “boys are better than girls” could be proved, but for government
Fig. 4.5
Five examples of the space test, correct answers in brackets [
18
]
