Changes

: The For [[opaque]] [[material]]s [[reflection]] depends on the [[colour]] of the [[material]]. Rough [[opaque]] [[material]]s such as paper will [[Diffuse Reflection|diffusely reflect]] and smooth [[opaque]] [[material]]s will [[Specular Reflection|specularly reflect]] such as [[metal]]s.: For [[transparent]] [[material]]s the chance of [[reflection]] at an [[interface]] depends upon the relative [[property|properties]] of those two [[media]] and the [[Angle of Incidence]]. [[Wave]]s that arrive at an [[interface]] where there is a large difference in [[density]] or [[Refractive Index|refractive index]] are more likely to be '''reflected'''.: The [[Electromagnetic Wave|Electromagnetic waves]] travelling through a more [[Optical Density|optically dense]] [[medium]] will engage in [[Total Internal Reflection|total internal reflection]] of at the [[interface]] with a less [[soundOptical Density|optically dense]] is called an [[echomedium]].