1. light Light allows us to see objects. Light comes from different light sources such as a lamp, a flashlight, and the sun.

2. light source the starting point of light Examples: lamp, flashlight, sun

3. path of light the direction light travels Light travels in a straight path in materials such as air, glass, and water.

4. straight path goes in one direction without any curves, bands, or angles

5. evidence an observation or information from data that gives support or proof of ideas and conclusions

6. light absorption the light that is taken in by an object This creates an increase in temperature.

7. light reflection the return of light rays from a surface

8. shadow a dark area that is formed when light is blocked by an object

9. variables the properties of things that can be changed in an investigation

10. Celsius the unit of measure for temperature 0 degrees = freezing 100 degrees = boiling

11. sound energy energy associated with the vibrations that produce sound It can change things.

12. sound produced by vibrating objects and vibrating columns of air

13. pitch a property of sound that is produced through vibrations

14. sound source the vibration or vibrating object that produces the sound

15. vibrations regular back and forth movements of objects Fast Vibrations = high pitch Slow Vibrations = low pitch