State the trend in the relative strength of van der Waals’ forces down Group 17.

To determine the trend in the relative strength of van der Waals' forces down Group 17, we need to consider the elements in this group. Group 17, also known as the halogens, includes elements such as fluorine, chlorine, bromine, iodine, and astatine.

Van der Waals' forces are weak intermolecular forces that arise due to temporary fluctuations in electron distribution. These forces can be categorized into three types: London dispersion forces, dipole-dipole interactions, and hydrogen bonding.

As we move down Group 17, the relative strength of van der Waals' forces generally increases. This is primarily due to the increase in the number of electrons and the size of the atoms.

Fluorine, the smallest halogen, has the fewest electrons and the smallest atomic radius. As a result, it experiences the weakest van der Waals' forces among the halogens.

Chlorine, with more electrons and a larger atomic radius than fluorine, experiences stronger van der Waals' forces.

Bromine, with even more electrons and a larger atomic radius than chlorine, experiences stronger van der Waals' forces than both fluorine and chlorine.

Iodine, with the most electrons and the largest atomic radius among the halogens, experiences the strongest van der Waals' forces.

Astatine, the heaviest halogen, would be expected to have the strongest van der Waals' forces. However, due to its rarity and radioactivity, it is difficult to study its properties accurately.

In summary, as we move down Group 17, the relative strength of van der Waals' forces increases due to the increase in the number of electrons and the size of the atoms.