Changes

: [[Alkene]]s are referred to as [[Unsaturated Hydrocarbon|unsaturated hydrocarbons]] because the [[Double Bond|double bond]] means it is not [[Saturated Hydrocarbon|saturated]] (full) with [[Hydrogen]] [[atom]]s.

: Testing for [[alkene]]s can be done by adding them to [[Bromine Water]]. If the [[Bromine Water]] turns from orange to colourless, then an [[alkene]] is present. During this test the [[Bromine]] [[Chemical Reaction|react]]s with the [[alkene]] to form a [[Dibromoalkane]].

: <chem>C2H4 + Br2 -> C2H4Br2</chem>