UNIT 9 HEAT TRANSEER : CONDUCTION After listening the presentation, how can you define 1. asbestos 5. Material 2.cork 6. Molecule 3. fiber-glass 7. Wool 4. handle

Based on a presentation about heat transfer and specifically conduction, here are definitions for the listed terms:1. **Asbestos:** A naturally occurring fibrous silicate mineral. Historically used extensively in construction due to its heat resistance and strength, but now largely banned due to its carcinogenic properties. Its microscopic fibers are excellent insulators because they trap air, hindering heat transfer.2. **Cork:** The outer bark of the cork oak tree. It's a naturally porous material, meaning it contains many small air pockets. These air pockets act as insulators, reducing heat conduction. It's often used in insulation and bottle stoppers.3. **Fiber-glass:** A material made from extremely fine fibers of glass. These fibers are woven together to create a mat or fabric. The air trapped between the fibers makes fiberglass an effective insulator, slowing down heat transfer. It's commonly used in insulation for buildings and appliances.4. **Handle (in the context of heat transfer):** A part of an object designed to be grasped by a person. In the context of heat transfer, a handle's material and design are crucial for preventing burns. Good handles are made from materials that are poor conductors of heat (e.g., wood, plastic) or have insulating layers to protect the user from heat.5. **Material (in the context of heat transfer):** Any substance with physical properties that affect its ability to conduct heat. Materials can be categorized as conductors (easily transfer heat) or insulators (resist heat transfer). The properties of a material, such as density, structure, and composition, determine its thermal conductivity.6. **Molecule:** The smallest unit of a substance that retains the chemical and physical properties of that substance. In the context of heat transfer, the movement and vibration of molecules within a material contribute to the transfer of thermal energy (heat). In conductors, molecules transfer energy more readily than in insulators.7. **Wool:** A natural fiber obtained from sheep and other animals. It's a good insulator because the fibers trap air within their structure. The trapped air pockets significantly reduce heat conduction, making wool effective for clothing and insulation.