Classify the following alkenes and their derivatives as `Z or E`
(i)
(ii)
Strategy: This method is preferable to the use of cis-trans beacuse it is not practical to identify cis and trans isomers when the four groups on `C=C` are different. The letter `Z` is used when the two high-priority substituets are on the same side of the double bond and the letter `E` is used when they are on the opposite sides (from the German words zusammen meaning together and entgegen meaning opposite), as shown: