Purpose: Learning Intention

– draw a light bulb from memory

– draw a light bulb from observation

– read about and complete a labeled diagram of a light bulb

TEACHER BACKGROUND INFORMATION:

* Read Teacher background information: It’s Electrifying page 23

LESSON:

1. Review last lesson and science chat-board.

* What have you learned about electric circuits?

* How do you draw and label an electric circuit?

* What interesting ideas were contributed on the science chat-board?

2. Explain that this lesson will focus on exploring light bulbs. Brainstorm places/ items that use light bulbs (household room lighting, streetlights, vehicle indicator lights, traffic lights and airport runway lights).

3. Students are to imagine and draw a light bulb in their science journals. Label it with any information they currently know (parts, materials used). Discuss the features and purpose of a labeled diagram (see note). Model how to draw a scale that is a horizontal line with a bar at each end, placed under the diagram with the size (eg. 1cm written under the line).

4a. After students have completed initial diagram, explain that they will be working in cooperative learning teams to explore and record observations of a light bulb. During this task they may now want to add to/ change their first diagram using a different colour – or start again? (see note).

4b. Model how to use a magnifying glass to look closely at the inside of a light bulb (see note).

5. Form teams, allocate roles, managers collect equipment.

6. After teams have completed their observations and drawings – share findings about the light bulb. Ask students to compare the drawing of the light bulb they did from memory with the one they did from observation. Discuss any differences and especially the importance of observation in scientists’ work. Further questions to encourage discussion include,

* What have you noticed about the light bulb?

* Why do you think the filament is that shape?

* What do you think the filament is made of?

* Where do you think the light bulb connects to the circuit?

7. Introduce and display an enlarged copy of ‘Inside a light bulb’ (Resource sheet 3). Explain that students will read it with their teams and complete the labeling activity. They are to highlight any interesting/ unfamiliar vocabulary as they read the text.

8. Now use student suggestions to label the enlarged copy of ‘Inside a light bulb’ (Resource sheet 3) – add to class science journal. Students modify their copy if required.

9. Compile a class list of their identified interesting/ unfamiliar vocabulary whilst reading text in step 7. Discuss the words and record students’ suggestions about how to describe them. Share dictionary investigations with class to locate the meanings of each identified word. Share meanings and record them on the keywords section of the class science chat-board.

10. Discuss the students’ ideas in relation to their findings. Ask,

* Why does the filament have the shape it does? (To increase the length of the filament. This increases resistance, which causes the filament to heat and produce light).

* What is the filament made of? (Tungsten)

* Why are there two different connection points? (For electrons to enter and leave the bulb, to create a circuit).

11. Update the class science chat-board