Chemistry-teacher education in Tanzania

Abstract

In science history formulae and first chemical equations have been developed during the 19^th century. In 1865 Kekulé proposed even the difficult benzene structure, afterwards other molecular structures came up with Van’t Hoff in 1874. Sometimes one can see today in different countries Chemistry education on this level of the 19^th century: only formulae and equations are taught and memorized by students. Arrhenius in 1884 developed first ideas to describe ions in acidic, basic and salt solutions, Laue and Bragg in 1912 and 1914 could finally solve the problem according to structures of salt crystals: Ions in ionic lattices and ionic bonding through electric forces have been described. After more than 100 years we should come up with differentiation between atoms, ions and molecules, and discuss besides atoms and molecules also the ions as smallest particles in our well-known substances at school. In Tanzania I could offer teacher training courses by Probono Schoolpartnerships for One World (Frankfurt, Germany, www.probono-oneworld.de) for 25 Chemistry teachers during eight years by one month in every year. So, I got the opportunity to do empirical research with the help of those teachers. Some results of empirical research in Tanzania and also in Indonesia show that Chemistry education doesn’t work well: There is nearly no knowledge about ions in solid salts, or about particles which can transfer protons or electrons by acid-base and redox reactions. Therefore, after instruction of important properties of matter in first lessons at schools, the article proposes how to introduce atoms, ions and molecules simultaneous during the first year of Chemistry lessons. These are the requisites to teach and to learn Chemistry on basis of smallest particles of matter and to interpret acid-base and redox reactions by transfer of protons and electrons. This way is well accepted by teachers and students, and Chemistry understanding will highly improve.