As a subject matter expert in materials science, I can explain the process of water absorption by paper. Paper is primarily composed of cellulose fibers derived from wood pulp. The structure of these fibers is such that they have numerous microscopic channels and capillary spaces within them. When paper comes into contact with water, the water molecules are attracted to the cellulose fibers due to hydrogen bonding. This bonding occurs because the oxygen and hydrogen atoms in the water molecules form a polar covalent bond, which can interact with the hydroxyl groups present in the cellulose.

The capillary action also plays a significant role in water absorption. Capillary action is the ability of a liquid, such as water, to flow against gravity through narrow spaces without the assistance of external forces. In the case of paper, the microscopic channels within the cellulose fibers act like tiny straws, drawing the water up into the paper. This process is aided by the adhesive forces between the water molecules and the cellulose, which are stronger than the cohesive forces within the water itself.

Additionally, the presence of voids (air pockets) within the paper structure allows for water to be absorbed and held in these spaces. As the water is drawn into the paper, it can cause the fibers to swell, which can lead to the paper becoming thicker and more rigid.

In summary, paper absorbs water due to the hydrogen bonding between water molecules and cellulose, the capillary action within the fibers, and the presence of voids in the paper structure.

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This is expected, as the tiny space between paper towel layers helps hold more water. Paper is made of cellulose, which water molecules like to cling to. As a result, paper readily absorbs water. Paper towels are especially absorbent because their cellulose fibers have empty spaces��tiny air bubbles��between them.read more >>