Final answer:
To assign the E or Z configuration to an alkene, substituents are ranked by priority according to the Cahn-Ingold-Prelog rules, mainly based on atomic number. In the given substituents, the priority order is I > CH₂I > CH₂ClCH₂ > F > H, allowing for the determination of stereoisomer configurations.
Step-by-step explanation:
In order to assign the E or Z label to an alkene, one must rank the substituents based on their priority following the Cahn-Ingold-Prelog priority rules. Priority is given based on the atomic number of the directly attached atoms. In this scenario, the substituents I (iodine), CH₂I (methylene iodide), H (hydrogen), CH₂ClCH₂ (1-chloroethyl), and F (fluorine) are ranked according to their atomic numbers: iodine (I), fluorine (F), chlorine (Cl), and hydrogen (H). The highest priority for substituents directly attached is iodine due to having the highest atomic number, followed by 1-chloroethyl and methylene iodide, which would be further distinguished by looking at the next atoms in the chain if necessary, then fluorine, and finally hydrogen. Thus, the order of priority is I > CH₂I > CH₂ClCH₂ > F > H for the given substituents. With this ranking, one can determine the configuration of stereoisomers as E (opposite sides) or Z (same side) based on which groups are on the same side of the double bond.