Q1: Property responsible for the talcum powder to cling to the skin is the

ANS:B - adhesion

Adhesion is the phenomenon where different substances are attracted to each other and stick together when they come into contact. It occurs due to intermolecular forces, such as van der Waals forces, hydrogen bonding, or electrostatic interactions, between molecules of the substances involved. Here's an explanation of adhesion:

1. Intermolecular Forces: Adhesion occurs because of the attractive forces between molecules of different substances. These forces can vary depending on the nature of the substances involved. For example, polar molecules may experience stronger adhesion due to dipole-dipole interactions, while nonpolar molecules may experience weaker adhesion due to dispersion forces.
2. Contact Surface: Adhesion typically occurs at the interface or contact surface between two materials. When two materials with different chemical compositions come into contact, the molecules at the interface interact with each other, leading to adhesion.
3. Surface Energy: The surface energy of a material influences its ability to adhere to other substances. Materials with high surface energy tend to have stronger adhesive properties because they form stronger interactions with other materials.
4. Applications: Adhesion is a fundamental property in various applications and processes, including:
   • Adhesive bonding: Glues, tapes, and adhesives rely on adhesion to bond materials together.
   • Surface coatings: Paints, coatings, and films adhere to surfaces to provide protection or decoration.
   • Biological adhesion: Cells and tissues in living organisms adhere to each other and to surfaces, facilitating physiological functions.
   • Microelectronics: Adhesion is crucial in microelectronics for bonding materials in integrated circuits and semiconductor devices.
5. Adhesion and Cohesion: Adhesion is often contrasted with cohesion, which is the tendency of molecules within the same substance to stick together. While adhesion involves different substances sticking together, cohesion involves the attraction between molecules of the same substance.