Unit 3 Lesson 10 Sources of Light--

Incandescent Light- Light bulb that has a wire and lights up when electricity passes through it. Air has been removed from the inside of the light bulb so the light will stay. Light that is produced when it gets hot enough.

Fluorescent Lights- Filled with gas that gives off ultraviolet light when electricity passes through it. In a process called fluorescent, a material absorbs light at one wavelength and then emits light at a longer wavelength. Fluorescent light bulbs emit light by causing phosphor to steadily emit protons. 

Laser- a device that generates a beam of coherent light. Laser light is emitted when excited atoms of a solid, liquid, or gas emit photons. 

Sodium Vapor Light-- As electric current passes through a sodium vapor bulb, it ionizes the gas mixture. The mixture warms up and the heat causes the sodium to change from a solid into a gas.