Investigating Light Properties

This activity is designed for students working in small groups to investigate light and some of its properties. Through observation and manipulating equipment students will conclude light travels in a straight line. They will be asked to show through drawings and written description what happened to the path of light when it comes in contact with an object. Questions will be generated for further investigation to reinforce their ideas. Groups will be asked to present their findings. The vocabulary words to be discovered are reflect, absorb, and redirect.

This 60-90 minutes activity is intended for 3rd grade students of science in a classroom setting. Students will be placed in groups of three or four. The room will need to be somewhat dark to conduct this activity.

Necessary equipment includes flashlights covered by black paper with a large pencil point sized hole in the middle, assorted prisms, mirrors, a piece of glass or Plexiglas, and other solid objects.

This is an introductory lesson into light.

Introduction:
* Students will write what they know about light in their science notebooks, share what they have written with others in a small group, and then these ideas will be written down on chart paper by the teacher for all to see.

* Introduce vocabulary: reflect, redirect, and absorb

* Do a class demonstration using a laser light showing stuents light travels in a straight line.

* Students will be shown the equipment they will be using; flashlight, assorted prisms, mirrors, solid objects, and pieces of glass or Plexiglas.

* The following questions followed by writing prompts predictions will be written into the student notebooks:
1. How does light travel?
I predict light will travel _________ because ________.
2. What happens to light when it comes in contact with an object?
I predict light will _________ when it comes in contact with an object because __________.

Activity:
* Student groups will shine the flashlight on each object. They will be asked to use their science notebooks draw what they observe, label it, and write about what happened with each object.

* Students will write a conclusion in their notebooks using the following prompt:
Today I learned ________. I know this because _____. Students will be encouraged to write down several "I learned ..." statements.

New Questions:
* Each student will be asked to write in their notebooks some new questions that could be investigated. Encourage them to avoid "yes/no" questions. Suggest their questions begin with "How" or "Why". These questions should be shared in their group.

Group Tie Up:
* Students will be asked to refer to their science notebooks to discuss their results.

* After this, vocabulary words, reflect, absorb, and redirect will be defined and written in their notebooks.

* Read about light from the student textbook.

Student Reflection:
* Students will write a paragraph in their science notebooks using their new vocabulary words.

I have never taught this particular lesson to 3rd graders before so the time element could be a factor either way. It would depend if this activity were done at the beginning of the year or at the end. I've incorporated some inquiry strategies and many students do not have the background and will need to be taught. This could also affect the time allotted.

Student notebooks will used for a formative assessment. The paragraphs on the reflection portion of the activity would determine if students had achieved the learning goal.

To further assess, students could be asked to answer one of their questions in another investigation.

* 3.1.1.2.4 Construct reasonable explanations based on evidence collected from observations
* 3.1.1.2.1 Generate questions that can be answered when scientific knowledge is combined with knowledge gained from one's own observation
* 3.2.3.1.3 Describe how light travels in a straight line until it is absorbed, redirected, reflected, or allowed to pass through an object.