Name: ___________________________________ Date: ____________________________________ Flynt - _____ Period _____th Grade Science Notes: Conduction, Convection and Radiation When people speak of heat, most of the time they are really talking about thermal energy. Scientists define heat as the transfer of thermal energy. Heat is caused by the motion of molecules that make up mater. All molecules are constantly in motion, but the speed of their motion varies. The ________________ the molecules are moving, the ________________ the substance is. Heat flows from ________________ objects to ________________ objects. Coolness is simply the absence of heat. Heat can be transferred by three principal means: __________________, _________________ and ________________. Conduction Conduction is the transfer of energy by _______________ contact. When molecules _______________ or bump into each other, heat energy is ________________ from faster moving, ________________ temperature particles to ________________ moving, cooler temperature particles. As they receive heat energy, the slower moving particles begin to move _______________ and their temperature _______________. They in turn continue to spread the energy by ____________ with other _________ moving particles and ________ them up. Heat energy is ________________ from ________ particle to another until ________ the particles in a substance are ________________ at the ________ speed. This process is known as ________________. Because this process involves a chain reaction with one particle colliding with the next and so on, the process of ______________ is sometimes nicknamed the ______________ ______________. Conduction occurs primarily in ___________ materials that are very _____________, because the particles are ______________ packed together. An orderly __________________ of particles also improves thermal conduction. Examples of good conductors include _______________, _______________, _______________ and _______________. _________________ are materials that are poor conductors. The particles in these materials are _______________ out and/or very ___________________. Examples of good insulators include _______________, _______________, _______________, and _______________. Convection Heat transfer also occurs in fluids, which include all _______________ and _______________. _______________ is the transfer of energy due to the movement of a heated fluid. When a liquid or gas is heated, the molecules move _____________, they ______________ more often and with greater force, and they begin to __________ out. This is known as _______________ _______________. If a fluid is heated from below, the portion of the fluid closest to the heat source will become less __________ than the fluid above it, which is located farther from the heat source. Due to the force of gravity, the ______________ dense fluid will begin to __________, which will displace the heated, __________ dense fluid, causing it to rise. The _______________ force is the name given to the upward force caused by differences in pressure and density within a fluid. If heat continues to be added to the fluid system, the resulting currents of liquid or gas are called _________________ currents. What does density mean? _______________________________________________________________________ What is the equation for density? Radiation _________________ is the transfer of __________ through the _______________ of space in the form of ________________________ __________, such as visible light and infrared rays. Conduction, Convection, and Radiation: How do these tie in with the Earth’s Atmosphere? __________________ _________________________ Sunlight travels through the vacuum of space and warms the ground when absorbed. Warm, less dense air rises. Cold, more dense air sinks. __________________________ The warm ground heats the air just above the surface by direct contact. Word Bank air all arrangement buoyant closely collide collide colliding conduction conduction conduction conduction convection convection convection convection cooler copper dense dense diamond direct disorganized domino effect electromagnetic waves energy energy faster faster faster gasses gold hotter Insulators iron less liquids more one quartz radiation radiation radiation rises rubber same sink slow- slower solid speed spread spread thermal expansion transferred transferred vacuum vibrating warmer warmer wood