Abstract:

Failure of students at universities results in loss of government subsidy as well as reduced progression of first year students to subsequent years of study. This is an undesirable situation and the institutions concerned are keen to iron out the causes. The first year subject, Chemistry 1, has been identified by Tshwane University of Technology (TUT) as one of the subjects with a high failure rate. Pre-tuition testing of all first year chemistry students over the past three years has revealed that students selected to enter the Chemistry 1 programme at TUT have inadequate understanding of several basic fundamental chemical concepts.
First year chemistry is mainly focussed on the inter-relationships of particles during changes of matter and many students have difficulty applying fundamental concepts, even those they are so familiar with they can repeat them from memory. The 2009 pre-test results for concepts related to conservation of matter was recorded at 23% with only a slight improvement to 29% on post-testing after completion of formal lectures. This poor performance clearly indicated the need to address this concept differently.
A targeted selection was made from the first year chemistry students admitted to TUT in 2010. “Lego’ building blocks were used by the students to allow them to represent the particles of matter involved in several examples of chemical change. Discussion groups were then used which allowed students to explain in their own words how matter had been conserved during the reactions they constructed. Pre- testing of all the examples used was done before students were shown how to use the ‘Lego’ blocks. The same test was used for post-testing at the end of the process.
The contribution of employing tactile models and active discussion as means towards improving students’ understanding of conservation of matter will be discussed in this paper.

Keywords:

first year chemistry students, conservation of matter, tactile models, focussed discussion.