Ch 19 Reflection Absorption and Refraction of Light

Ch. 19: Reflection, Absorption, and Refraction of Light Vocabulary: reflection, absorption, transmit, refraction

When Light Strikes an Object • Light travels in a straight line. • It will continue moving in a straight line, until it hit something. • Depending on what it hits, light may behave in very different ways.

Reflection • When light bounces off a surface, it is called reflection. • When light is reflected it travels in a straight line away from the reflecting surface. • Example of Reflection: http: //www. openschool. bc. ca/elementary/scien ce 4/html/bouncing. Light. htm

Absorption • Any time light hits a surface, some of it is absorbed, or taken in. • When light is absorbed into a surface it is transformed from light energy, into heat energy. • That is why on a sunny day it is cooler to wear a white tshirt, than a black t-shirt; dark surfaces absorb more light than lighter surfaces.

Refraction • Some materials transmit light, or allow light to pass through them. • These transparent materials cause light to bend as it is passing through the surface. • When the light bends, it makes things look like they do not match up.

Questions About Chapter 19 1. Which color absorbs the most light? 2. When light bounces off a surface, what is it called? 3. Describe what happens to light when it passes through glass or water. 4. What happens to a material when it absorbs light? 5. On a summer day, why is blacktop so much hotter than the dirt next to it?