Happy voices fill the air! Twenty students and 5 teaching assistants are seated in groups waiting for the lesson to begin. I was back in Taiwan this summer teaching and consulting with a very special program called Science for All. This year sixty six students who are blind, visually impaired and deafblind in grades 1 through 12 participated.
Classes were held at a vocational school affiliated with National Changhua University of Education. The teaching assistants were all students at the university, majoring in either science education or special education. Many are in Master degree programs. The professors from the university and teachers from local high schools are the faculty for the program. It was so wonderful to be a part of this group once again. A teaching assistant who is majoring in chemistry interpreted for me as I taught.
Hands-On Lesson to Create Rubber
Every teacher chose hands-on activities for the students to do, varying the content so that the concepts involved were at the appropriate grade level, but the activities involved the same materials. For example, the activity I chose was creating a substance that is very similar to rubber. The commercial version is called Silly PuttyTM. The materials needed for this activity were white glue, water, and Borax powder. The equipment required was sturdy paper cups, measuring spoons, and wooden stirring sticks. In my classroom I use craft or Popsicle sticks. In this case we used disposable chopsticks! They worked very well.
The concepts being taught included properties of matter, physical and chemical changes. For the youngest group of students, the concepts explored related to properties of matter. As the activity was carried out, students observed that the glue was sticky! And as they added the water to Borax powder and stirred, they could feel using the stick that the powder gradually dissolved, with the sandy, gritty texture changing as that happened. An important part of science is making predictions about what might happen. So after making observations about the physical properties of the two substances, students were asked to guess what would happen when the two substances were mixed together! “Explode” was a popular response!
Luckily the chemical reaction that occurred was not exothermic (giving off heat), so it did not explode! However, the resulting product had some very interesting properties. The white blob felt a bit wet and slimy! When encouraged to knead the material with their hands, students could hear bubbles of air popping and water dripping. The substance gradually became less slimy, smoother and resilient. As students observed the properties of this new substance, they were asked to try stretching it, bouncing, it and to make it into a variety of shapes.
Understanding Chemical Reactions
With the older students the concepts learned involved understanding that a chemical reaction creates something that is completely different from the substances that were the reactants. And with the high school students there was a discussion of cross-linked polymers, which was what was made in this experiment! The observations of the properties of the newly created substance were much the same for the older children as they were for the younger children.
For me, one of the most memorable moments of this time in Taiwan was watching as a young man who is deafblind following the instructions that his teaching assistant gave to him by writing Chinese characters on the palm of his hand with her finger. As he proceed through the experiment, a growing sense of understanding appeared on the young man’s face. And as he explored how the material responded to his touch, a smile formed as he showed me a gracefully shaped small bowl that he created. That smile banished all the feelings of jet lag I was undergoing. I wish I had a picture of the young man, but the memory will last, along with so many other special moments. The experiences both last year and this make me so glad that I became a teacher! One of those happy voices was mine!