Chemistry · States of Matter - Gases, Liquids and Solids

The correct answer is Option E: He. Helium is a noble gas characterized by its minimal atomic size and the lowest number of electrons among the options provided. This results in the weakest London dispersion forces. In comparison, F2 has more electrons than He, giving it stronger dispersion forces. Cl2 and Br2 are larger and have more electrons, further increasing their dispersion forces relative to He. I2 is the largest and heaviest, possessing the strongest dispersion forces of all.

F2: While it is small, it has more electrons than helium, resulting in slightly stronger dispersion forces compared to He.

Br2: Being larger and heavier, it exhibits stronger London dispersion forces than both F2 and Cl2 due to greater electron count and surface area.

Cl2: Larger than F2 and contains more electrons, leading to stronger dispersion forces compared to both F2 and He.

I2: The largest and heaviest molecule among the options, it possesses the most substantial dispersion forces due to its size and electron count.

He: As a noble gas with a very small atomic size and the fewest electrons, it has the weakest London dispersion forces.