I get so confused when it comes to making isomers for a compound like propanol,di ethyl ketone and those which has double and triple bonds. It seems I can make an isomer by changing the position of double bonds too. Isn't there any easy way to do it? Also When I come up with 4 isomers for a compound,internet already contains 8 of them and then I wonder why I didn't get the idea to arrange them into four more by changing the positions further more.It would look as if the 4 isomers I came up with are the only ones available until I get to refer the websites. So is there any way to check whether the number of isomers I came up with are correct ones?