| A | B |
|---|
| electromagnetic waves | a wave that consists of electric and magnetic fields that vibrate at right angles to each other. They can travel through empty space or matter. |
| electromagnetic spectrum | all of the frequencies or wavelengths of electromagnetic radiation |
| wavelength | is the distance from any point on a wave to an identical point on the next wave |
| matter | anything that has mass and takes up space |
| Infrared waves | EM waves that are important to living things. They warm things up on earth. All things give off these waves. Warmer objects give off more of these type of waves. |
| Visible light | a very narrow range of wavelengths that humans can see. It is changed into chemical energy by photosynthesis. |
| Visible spectrum | The range of visible light a person can see. |
| Ultraviolet light | another kind of electromagnetic wave. It can cause sun burn, skin cancer, wrinkles, and damage the eyes. It also kills bacteria on food and surgical tools. It also supplies Vitamin D which helps your teeth adn bones become strong. |
| Reflection | is the bouncing back of light rays when they hit an object. |
| Law of Reflection | states that the angle of incidence is equal to the angle of reflection. For example, if you throw a ball straight down, it will bounce straight up. It does not change direction |
| Incidence | is the arrival of a beam of light at a surface |
| Regular reflection | when light beams are reflected by all points at the same angle -like in a mirror |
| diffuse reflection | Light beams hit the surface and reflects at many different angles. Like off a wall |
| lumious | objects that emit visible light |
| illuminated | a visible object that is not a light source.-For example the Big "A" |
| absorption | the transfer of energy carried by light waves to particles of matter |
| scattering | an interaction of light with matter that causes light ot change direction |
| transmission | the passing of light through matter. Without this you couldn't see |
| transparent | You can see objects clearly when they are visible through this. For example air, glass and water |
| translucent | transmits light but also scatters the light as it passes through matter. For example-wax paper |
| pigment | material that gives a substance its color by absorbing some colors of light and reflecting others. |
| a medium | a substance through which a wave can travel |
| refraction | the bending of a wave as it passes at an angle from one medium to another. |
| lens | is a transparent object that forms an image by refracting, or bending light |
| convex lens | A lens that is thicker in the middle than at the edges |
| concave lens | a lens that is thinner in the middle than at the edges |
