The idea of learning about one’s surrounding through experimentation goes as far back as the 1600’s. It was during that time that a French scholar, Pierre Gassendi, “was on of the first to suggest that the proper way of learning about the universe was to carry out experimentation.”.1 Vast amounts of information pertaining to the make up of the world around us came from men using experiments to make investigations. This is especially true in chemistry. Much of the understanding of the structure of molecules and even their existence, not to mention atoms, was obtained in this fashion.
As stated in Professor McBride’s seminar description of “How Do You Know? the Experimental Basis for Chemical Knowledge”, it is much more beneficial for science students to “understand the logic of inference from experimental evidence” than to just accept information on the basis of being told. The goal of this unit is to allow students to gain an understanding through personal experience and a historical look at certain scientific discoveries of how research works. It can be used as an introduction to a major chemistry unit of a physical or integrated science course. A unit on matter that would include the definition of matter, explanation of the properties of matter (physical versus chemical, volume, mass, and density), as well as the states of matter and its phases should be covered before this one is used. Students should also be familiar with the metric system and how to use it in taking measurement. It may be necessary, depending on the backgrounds of the class to begin the unit with a review on how to conduct an experiment. The unit should take between two and three weeks. This would depend on where one starts with the unit. The target audience would be high school students who have very limited science backgrounds regardless of what grade level they are in. My hope is that upon completion of this unit, students will have gained an appreciation for the information they will learn; recognizing that the facts just didn’t come out of thin air but came from evidence obtained through actual experiments. Perhaps this will facilitate their future learning.
During the first week or following the review, students will perform various activities and experiments. The purpose of this is to give the students practical and personal experience in obtaining information about something through experimentation. These exercises will investigate the following topics:
1. Physical properties of matter.
2. An example of a chemical reaction.
3. The use of experiments to gain indirect evidence on an object.
The second week will involve the students studying a few experiments that were done in the past. These will come from the history of chemistry. The objective for this part of the unit is that by studying the purpose, procedure, and results of these experiments, students will be able to give examples of the types of information scientists can gain from experimentation.