Question

which of the following most likely requires intermolecular forces?
a spider walking on the bottom of a leaf
a rock maintaining its solid shape
a koala using claws to hold onto a tree
a piece of fruit falling from a branch to the ground

Explanation:

Intermolecular forces are responsible for the interactions between molecules. A spider walking on the bottom of a leaf is able to do so due to van - der - Waals forces (a type of intermolecular force) between the tiny hairs on its feet and the leaf surface. A rock maintaining its solid shape is due to intramolecular (covalent, ionic etc.) bonds within the rock's structure, not intermolecular forces. A koala using claws to hold onto a tree is a mechanical interaction. A piece of fruit falling from a branch to the ground is due to gravity.

Answer:

a spider walking on the bottom of a leaf