# big idea 11:

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Big Idea 11:. Energy Transfer and Transformations A. Waves involve a transfer of energy without a transfer of matter. B. Water and sound waves transfer energy through a material. C. Light waves can travel through a vacuum and through matter. - PowerPoint PPT Presentation

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Big Idea 11 :

Big Idea 11:Energy Transfer and Transformations

A. Waves involve a transfer of energy without a transfer of matter.

B. Water and sound waves transfer energy through a material. C. Light waves can travel through a vacuum and through matter. D. The Law of Conservation of Energy: energy is conserved as it transfers from one object to another and from one form to another.

Benchmark Number & Descriptor

SC.7.P.11.1Recognize that adding heat to or removing heat from a system may result in a temperature change and possibly a change of state.SC.7.P.11.2Investigate and describe the transformation of energy from one form to another.SC.7.P.11.3Cite evidence to explain that energy cannot be created nor destroyed, only changed from one form to another.SC.7.P.11.4Observe and describe that heat flows in predictable ways, moving from warmer objects to cooler ones until they reach the same temperature.

Temperature Measure of kinetic energy of moleculesMeasured with a thermometer3 ScalesFahrenheitCelsiusKelvin

F = Fahrenheit (used for weather)Water boils at 212F.Water freezes at 323 F.

C = Celsius (used in science)Water boils at 100C.Water freezes at 0C.

K = Kelvin(used in science)Only scale that has absolute zeroParticles are said to have no movement at this temp.

Thermal EnergyThe total energy of the particles in a materialDepends on temperature, mass, and type of substanceWhich beaker of water has more thermal energy?B - same temperature, more mass

200 mL80CA400 mL80CB*07/16/96*##HEATHEAT is the transfer of energy from one object to another when the two things are at different temperatures and in some kind of contact. Always transfers from hot to coldEx: Teapot heats on stove top cup of tea cools down (loses energy as heat)

Heat TransferHeat is always transferred from hot to cold.

Heat is transferred by conduction, convection, and radiation.

*07/16/96*##KNOWLEDGE CHECK ____ is a measure of how quickly atoms are moving.

A ____ measures the temperature of matter.

The total amount of ____in an object is known as thermal energy.

Which object has more thermal energy: Cup of coffee at 80F or a bathtub filled with coffee at 60F?

KNOWLEDGE CHECK TEMPERATURE is a measure of how quickly atoms are moving.

A THERMOMETER measures the temperature of matter.

The total amount of KINETIC ENERGY in an object is known as thermal energy.

Which object has more thermal energy: Cup of coffee at 80F or a bathtub filled with coffee at 60F?BATHTUB = more particles, more energy

TRANSFER of ENERGY

TRANSFER OF THERMAL ENERGYThermal energy is always moving all around you.Thermal energy affects your life in very important ways.Changes in weather, cooking your food, and heating your house are a few of the ways the transfer of thermal energy helps us.

The transfer of heat by direct contact between objects or particlesConduction

Heat transferred by the movement of molecules within a substance

Movement occurs from warmer areas to cooler areasConvection

Heat transferred through space in the form of waves

EXAMPLE: The suns rays causing a sunburn

Helping or Slowing the Flow of EnergyCONDUCTORINSULATORConductors are materials that transfer heat easily.Examples: metals like copper and gold

An insulator is a material that does not transfer heat easily. Examples: liquids and gases jacket

KNOWLEDGE CHECK What examples of thermal energy and thermal energy transfer can you see around you right now?

KNOWLEDGE CHECK What examples of thermal energy and thermal energy transfer can you see around you right now?Microwave, sun = radiationStove/pan, spoon in heated pot = conductionAir currents = convection

MATTER and HEATMATTER and HEATStates of MatterEnergy and MatterSOLID = particles are close together, move slow (vibration)LIQUID = particles spread apart, slide past each otherGAS = particles move fastest, move everywhere (spread out)Solid = least amount of energyLiquid = medium energyGas = most energyEnergy is related to particle movement. PHASE CHANGE and ENERGYPhase changes occur when an objects state of matter change.

In order for a change in phase to occur, energy must be either released or absorbed.Solid -> LiquidMeltingEnergy is absorbed.

Liquid -> SolidFreezingEnergy is released.

Liquid -> GasVaporizationEnergy is absorbed.

Gas -> LiquidCondensationEnergy is released.

Solid -> GasSublimationEnergy is absorbed.

KNOWLEDGE CHECK Identify whether energy needs to be absorbed or released in the following scenarios:Ice cube meltingBoiling waterDry ice placed in the airDew forming on grass

KNOWLEDGE CHECK Identify whether energy needs to be absorbed or released in the following scenarios:Ice cube melting ReleasedBoiling water AbsorbedDry Ice placed in the air AbsorbedDew forming on grass Released