Chemistry Reference
In-Depth Information
effects (see E2.5) safely. In an experimental training for school experiments,
students have to prove these skills and abilities to demonstrate those experiments
and to perform experimental lectures at school safely. Already working teachers
should also test new spectacular experiments for themselves, before going into the
classroom with those experiments. Only after elimination of potential hazards one
can go into school classes and perform those experiments, albeit with all required
safety equipment: goggles, safety screen, splinter basket, etc. To be able to survive
a whole “Christmas lecture” unharmed, the teacher will need long experience with
experimentation. Finally, they must follow the relevant regulations with regard to
hazardous materials (see Chap. 5).
To exploit the many opportunities for motivation, a well-founded scientific
education in chemistry is required besides the experimental skills. You need not
only to assess spontaneous students' remarks scientifically correct - you will also
try to produce a suitable cognitive conflict for motivation. You also want to be
flexible and create suitable experiments for motivation in many teaching situations.
The beginning teacher will first demonstrate only scheduled or carefully planned
experiments - the experienced teacher should be capable to demonstrate spontane-
ously created experiments or to start students' own experiments for a special
question, and to contrast students' misconceptions with suitable experiments.
2.4 Human Element: Motivation Through Everyday
Language and Media
Expressions of the everyday language often obscure the scientific facts on the one
hand - on the other hand there are occasions to arise motivation to think about these
issues.
Statements such as “the copper roof is green” are made in everyday language and
lead to the idea that copper could be red-brown on one side and appear green on the
other side. If we start from the knowledge of specific properties that distinguish
certain substances, it is clear that only one of the colors should be specific for
copper. In this way, the cognitive conflict or inconsistency is produced and students
may be motivated to reflect on the “change of copper color.” The result of those
reflections should be the finding that the green substance is a compound of copper -
in this case a basic copper carbonate, which forms by the reaction of carbon dioxide
containing rain water a green layer on the red-brown metal. An experimental
verification of this assumption can follow and eliminate the incongruence.
The media often provide statements that may unintentionally lead to motivating
discussions. If a journalist commented about a factory fire in the words: “there are
no chemicals involved in that fire” students may use their knowledge and conclude
that all fuels are chemicals, and that even the oxygen of the air is regarded as a
chemical, which is involved in every fire. The discrepancy between the statement of
