Light Properties
Elementary School
Definition
Characteristics of light, including that it travels in straight lines, can be blocked by objects to form shadows, and can be reflected off surfaces or bent when passing through materials. These properties explain how we see and use light.
Worked examples
A flashlight beam travels in a straight line until it hits a mirror, then bounces off at the same angle.
Light's straight-line travel and reflection off the mirror surface are key properties at work.
A hand placed between a lamp and a wall casts a shadow because the hand blocks the light rays.
Light travels in straight lines and cannot bend around the hand, creating the dark shadow area.
A straw in a glass of water looks bent at the surface because light bends when entering the water.
Light changes direction (refracts) when passing from air into water, shifting how we see the straw.
Common mistakes
- Light bends around objects, so shadows have fuzzy edges everywhere. → Light travels in straight lines; fuzzy shadow edges come from the light source size, not bending around objects. Light does not curve around opaque objects — shadows form because light is blocked in straight paths.
- Reflection and bending (refraction) are the same thing. → Reflection bounces light off a surface; refraction bends light as it passes through a different material. Reflection happens at a surface boundary; refraction happens when light enters a new medium.
Where you'll use it next
You'll apply light properties when studying mirrors and lenses in optics, explaining how eyes and cameras work, understanding fiber optics and rainbows, and exploring waves and electromagnetic radiation in physics.
See also
Reviewed by Pat Cheng, M.Ed. — StudyPug Curriculum Lead · Last updated June 6, 2026