Lesson Observation

Physical and Chemical Changes

Introduction to this lesson started with gaining the student's attention by means of a question.

The teacher asked students if they knew the difference between a physical and a chemical change? She asked them if crushing a sugar cube and dissolving it in water, was a physical or a chemical change? Some students said it was physical, and others said it was a chemical change.

Teacher let them reflect on the question and at the same time, demonstrated the process in front of them, and informed them of today, they would be learning the difference between a physical and a chemical change, she also linked the question to students prior lesson knowledge. Students who said it was a chemical, said " You see, Ms. the sugar is gone with the water! She also gave another example of water and ice cubes, showed them water in a bottle, and then ice-cubes already made, and asked them if the water changed? Students were not sure of what to answer and this made the activity more interesting to all of them. Teacher explained that if the ice cube had something different in it other than water, and students then realized, that the ice cube was still water, but in a different form of matter.

Teacher explained to them that when you have an element and it does not create a new substance, that it is considered to be a physical change, that only when an element creates a new substance, that it is then a chemical change! Students loved the example, and became fully engaged.

She then had them watch a "brain pop video" explaining changes, and put them into groups to work on the activity. She went around the desks, becoming available to them, not only monitoring them, but explaining questions asked, and at the same time assessed their comprehension on worksheet activity. Even though this was a worksheet activity, teacher applied manipulating procedures of showing water and sugar cube, to reflect real-world produced products using a kinesthetic learning approach.