Grade 7 Lesson
Do Now:
Complete the radiation, Conduction, Convection Practice Worksheet
Homework:
Study Guide: Thermal Energy Transfers Quiz
Today’s Agenda:
Review Convection Notes As needed - Periods 6, 7
Convection is the movement of thermal energy by the flow of material in a fluid.
Fluids are liquids or gasses.
when the particles of a fluid move from one place to another, they carry their thermal eenrgy alogn with them.
Convection occurs Because of changes in density.
When a fluid is heated, its particles move faster and spread out.
This causes the fluid to becoem less dense where it is ehated.
Less dense fluids are buoyant - so they rise.
Where fluids cool, the particles slow down and contract.
This causes it to become more dense where cooling ocurs.
The dense, cooler fluid sinks.
This rising and sinking can create a covection current
see digram below.
Convection currents are found in a boiling pot of water as well as Earth’s atmosphere
