Question

Почему сухие стеклянные пластинки не слипаются, а мокрые слипаются?

Answer 1

Поверхностное натяжение отвечает за силу межмолекулярного сцепления между молекулами воды+воды и воды+стекла.
Тут в основном работает сцепление воды со стеклом.

Answer 2

Why don't dry glass plates stick together while wet ones do?

When it comes to the question of why dry glass plates do not stick together while wet ones do, it is important to understand the underlying principles of adhesion and cohesion.

Adhesion refers to the attraction between molecules of different substances, while cohesion refers to the attraction between molecules of the same substance. In the case of wet glass plates, the water molecules on the surface of the plates exhibit both adhesion to the glass and cohesion with each other. This creates a strong bond between the plates, causing them to stick together.

On the other hand, dry glass plates do not have a layer of water molecules on their surfaces. Without the presence of water, the adhesion between the glass molecules is weaker, and the plates do not stick together.

It is worth noting that the adhesion and cohesion properties of a substance can be influenced by various factors, such as the surface roughness of the material, the presence of impurities, and the temperature. However, in the case of dry and wet glass plates, the primary factor at play is the presence or absence of water molecules on the surface.

To summarize, dry glass plates do not stick together because the absence of water molecules reduces the adhesion between the glass surfaces. Wet glass plates, on the other hand, have a layer of water molecules that create strong adhesion and cohesion forces, causing them to stick together.