Chapter Four: Chemistry and Physics Connections 4.1 Elements, Compounds, and Reactions 4.2 Carbon Compounds and Cells 4.3 Light and Living Things

4.3 Light and living things The microscope magnifies objects so you can see their very small features. Light is very important to all living things.

4.3 Light Light is a form of energy. Light given off from objects like a light bulb or the Sun travels in lines.

4.3 Reflection Reflection occurs when light bounces off of a surface.

4.3 Law of reflection The incident ray is the light ray that strikes the surface of the mirror. The reflected ray is the light ray that bounces off the surface of the mirror.

4.3 Reflection Surfaces, such as polished wood, are in between smooth mirrors and rough concrete and create two types of reflection.

4.3 Refraction Refraction is the bending of light as it crosses a boundary between two different transparent materials.

4.3 Refraction Do you think this illusion would still happen if there were no water in the glass? Try it and see.

4.3 Lenses A lens is an object that is designed to refract light in a specific way. Many devices you use contain lenses.

4.3 Lenses There are two basic kinds of lenses: –convex –concave

4.3 Lenses Light rays that enter a convex lens parallel to its axis refract and meet at a point called the focal point.

4.3 Lenses Light rays that enter a concave lens parallel to its axis refract and spread out

4.3 Microscopes Most microscopes use at least two lenses. The lens closest to the object to be viewed is called the objective. The lens you look through is called the eyepiece.