Experiments - Essentials of Chemical Education - page 121

Fig. 5.1 First elements and the atomic mass table of Dalton in 1808 [ 2 ]
atomic mass and published in 1808 his famous “New system of chemical philoso-
phy” with the first atomic mass table in science (see Fig. 5.1 ). With this hypothesis a
lot of new research could start, the whole ideas about elements and compounds,
about composition of elements and compounds, about formulae, equations and
stochiometry were born. But as mentioned Dalton regarded a lot of today's
compounds as elements: magnesia, lime, soda, potash, strontian, and baryt -
“they were elements for Dalton and his aspects.”
5.1 Scientific Ideas: Experiments, Experimental Skills, Safety
As discussed, chemistry developed to an experimental science. Another set of basic
questions of chemistry education concerns the role of the experiment in Chemistry,
in which way this role also applies to chemistry lessons and which other functions
need to be added in this regard. In chemistry education the scientific functions have
to apply, but there are also other functions of the experiment like motivation,
simulation, or illustration.
Experiments and processes of knowledge construction: One of the most impor-
tant roles of the experiment in chemistry is to gain scientific and empirical knowl-
edge through experimental proofs of hypotheses under controlled and
systematically modified conditions. In the introduction, the evolution of “elements
and compounds” is outlined as a fundamental historical example. Three other
historical examples will be given. First, the empirical method of perception shall
be formalized by outlining the key steps of proving hypothesis (see Table 5.1 ).