Reflexions on science

A plea for the teaching of Chemistry Why must the teaching of this science always pass initially through the theoretical aspects (and especially at the college level ). Talking about the structure of the atom without any experimental experience seems to me very boring and even a hindrance. For example, in order to explain chemical bonding, why not use the approach of first showing that chemical elements can attract and repel one another as in everyday life where some people are always together and others constantly try to avoid one another. Chemical elements fall into groups as do membres of a family within human families. They are called halogens or alkalines or noble gazes etc. Chemical elements can be attracted one another and come together to produce chemical reactions giving products which differ from their parents but keeping their parents origins, e.g. sulfur (S) combines with iron (Fe) to form iron sulfide (FeS). The chemical bonds between elements have different properties depending on whether each shares a half of their property in common (covalent bonding), or if one gives everything to the other (ionic bonding) or whether everything is shared regardless to whom it belongs (metallic bonding). Why don’t we explain the structure of objects that surround us, such as wood, glass, water and oil, the salt or the air we breathe ? All are solids, liquids or gases resulting from forces of attraction or repulsion. Where does this come from ? Why do some substances have a pleasant aroma and others are disagreeably smelly ? What is color and how can we explain its formation? Why is green the dominant colour in nature? What is its origin? What about fluorescent or luminescent objects? What in fact is light ? In trying to answer all these questions chemistry is part of the experimental sciences and we need to perform experiments to achieve a better understanding of the theoretical aspects of chemistry. For example, if I put a piece of copper in nitric acid, which gas emerges and how do I explain this transformation? How does a chemical battery work and what is its application in the electric industry ? Yes, one should aboard chemistry in the first instance through observation and practical experience to explain this subject’s interest to everyday life. Then in the second instance one can proceed confidently toward the theory and explain in depth the remaining questions. The opposite may be anti-pedagogic and ready boredom. Remember: Chemistry is an experimental science and the theory is based on experimentation and observation of natural phenomena and performing experiments in the laboratory . Raúl Mariaca                                                                                                       3 Novembre 2012