luminous object: something that produces its own light

The Moon is bright only because it reflects the Sun’s light. Therefore, theMoon is NOT luminous.

1. Incandescence: light that is emitted from a very hot object

sodium vapour lamps

a) electric discharge

neon lights

2. Luminescence: light that is generated without heating the object

- types:

LEDs(light-emitting diodes)

b) chemiluminescence: light that is produced by a chemical reaction without a rise in temperature

c) bioluminescence: light that is produced by a biochemical reaction in a living organism

and mercury

d) fluorescence: light that is emitted during exposure of the source to ultraviolet (UV) light

compact fluorescent light (CFL) bulbtubular fluorescent light bulb

Uses of Fluorescence

forensic science

black light theatre

fluorescent fish

money

e) phosphorescence: light that is emitted due to exposure of the source to UV light, and that continues to be emitted for some time in the absence of the UV light

Reflection diagram

Characteristics of Images

Size bigger or smallerAttitude upright or invertedLocation closer or fartherType real or virtual

Curved mirrors

Lens and mirror equation

Refraction diagram

Index of refraction

n =c/vC-speed of light in a vacuum 3.0 x 10 8m/s

V-speed of light in medium

Internal reflection

Lenses

Diverging lens

The eye

Colour Theory