Which alkyl halide has the maximum density?

The compound with the maximum density among the given alkyl halides is CH3I (methyl iodide). Density is influenced by both the mass of the molecules and their volume. In this series of compounds, the halogen atoms are heavier as you move down the group in the periodic table.

CH3Cl contains chlorine, CH3Br contains bromine, CH3I contains iodine, and CH3F contains fluorine. Since iodine has the highest atomic mass of these halogens, CH3I has a greater mass compared to the others, which contributes to a higher density.

Although molecular shape and size can also affect density, for these simple alkyl halides, the most significant factor is the mass of the halogen. Therefore, CH3I, having the heaviest halogen, exhibits the maximum density of the options presented.