What are cohesive forces?

Cohesive forces refer to the interactions between like molecules, specifically the forces of attraction among particles within a liquid. These forces are responsible for the phenomenon of surface tension, where the liquid's surface behaves like a stretched elastic membrane. For example, in water, hydrogen bonding creates strong cohesive forces that allow water droplets to form and hold together rather than spreading out.

This strengthening of the molecular interactions within the liquid enables various phenomena, such as water's ability to rise in narrow tubes (capillary action) and the formation of raindrops. Understanding cohesive forces is essential in studying fluid dynamics and the behavior of liquids under different conditions.

The other options describe different kinds of interactions. For instance, attractions between different materials relate to adhesive forces, which are not cohesive. The forces of attraction among particles of a gas pertain more to gas dynamics and intermolecular forces in gaseous states. Magnetic forces in liquids would typically involve specific conditions that do not fall under the general definition of cohesive forces. These distinctions highlight the unique nature of cohesive forces as they apply specifically to the attraction between identical molecules in a liquid state.