How do you differentiate between alkanes and an alkene?

An alkane is a saturated hydrocarbon, which basically means it is an compound made up of carbons and hydrogens (hence the hydrocarbon) and has the maximum number of hydrogens (hence it is saturated). Whereas, an alkene while also being a hydrocarbon is unsaturated, due to a double bond between two carbons meaning that one of the carbons is only bonded to one hydrogen and the other carbon is bonded to two hydrogens, whereas without the double bond as seen by the alkane, the alkene could have another two hydrogens. So simply an alkene has a double bond which means that it cannot fit the maximum number of hydrogens and therefore is unsaturated. Therefore by using a diagram you can differentiate an alkene from an alkane due to the double bond. Another common way of differentiating between them is using bromine water. When alkenes are mixed with bromine water the colour will change from orange to colourless.