Final answer:
Ethylene glycol will dissolve in ethanol due to both being polar, while iodine will dissolve in carbon tetrachloride because they are both nonpolar.
Step-by-step explanation:
When considering the solubility of substances like ethylene glycol and iodine in different solvents, the principle of 'like dissolves like' applies, indicating that polar solvents dissolve polar substances and nonpolar solvents dissolve nonpolar substances. Ethylene glycol, which is a polar molecule due to its -OH groups, will dissolve in ethanol, which is also a polar solvent. On the other hand, iodine, which is nonpolar, is more likely to dissolve in nonpolar solvents such as carbon tetrachloride (CCl4), which cannot form hydrogen bonds and has a similar non-polar character.