What is Heat?

• Heat is the energy of particles moving from warmer regions to cooler regions.

• Atoms are always moving and the motion of these particles result in heat.

HeatHeat

All matter has heat even All matter has heat even an ice cube. As more an ice cube. As more heat is added to the heat is added to the ice the molecules will ice the molecules will move faster and move faster and eventually spread far eventually spread far enough apart to enough apart to become a liquid.become a liquid.

Heat on the moveHeat on the move

Heat moves from a Heat moves from a warmer substance to warmer substance to a cooler substance.a cooler substance.

TemperatureTemperature Temperature is the Temperature is the

measure of the average measure of the average kinetic energy of the kinetic energy of the particles in a sample of particles in a sample of matter.matter.

As the particles move As the particles move faster and their average faster and their average kinetic energy becomes kinetic energy becomes greater the temperature greater the temperature rises.rises.

Heat and Temp not the sameHeat and Temp not the same

Heat is the total kinetic Heat is the total kinetic energy of all the energy of all the particles in the sample.particles in the sample.

Temperature is the Temperature is the measure of the measure of the average kinetic energy average kinetic energy of all particles in a of all particles in a sample.sample.

Heat is measured in a unit Heat is measured in a unit called caloriecalled calorie..

A calorie is the amount of heat A calorie is the amount of heat needed to raise the temperature needed to raise the temperature of one gram of water 1 degree of one gram of water 1 degree

celsius.celsius.

Thermal EnergyThermal Energy

Thermal energy is related to the Thermal energy is related to the energy of the particles that make energy of the particles that make

up matter.up matter.

Thermal EnergyThermal Energy

Is the total energy of particles in the Is the total energy of particles in the material.material.

This total includes both kinetic and potential This total includes both kinetic and potential energy.energy.

Kinetic refers to motion/vibrationsKinetic refers to motion/vibrations Potential refers to forces that act within or Potential refers to forces that act within or

between the particles.between the particles.

Thermal EnergyThermal Energy

The more mass a The more mass a material has at the material has at the same temperature the same temperature the more thermal energy it more thermal energy it has.has.

Specific HeatSpecific Heat

The amount of energy The amount of energy required to raise the required to raise the temperature of 1 kg of temperature of 1 kg of a substance one kelvin a substance one kelvin is called its specific is called its specific heat.heat.

Measured in joules per Measured in joules per kilogram per kelvinkilogram per kelvin

J/ (kg x K)J/ (kg x K)

Specific HeatSpecific Heat

Temperature does not rise and fall at the Temperature does not rise and fall at the same rate for all objects.same rate for all objects.

The amount of heat required to raise the The amount of heat required to raise the temperature depends on the chemical temperature depends on the chemical makeup of the material. makeup of the material.

Different materials need more or less heat to Different materials need more or less heat to change their temperature by the same change their temperature by the same amount.amount.

Freezing and boiling pointFreezing and boiling point

ScaleScale Freezing Freezing

PointPoint

Boiling Boiling

PointPoint

AbsoluteAbsolute

ZeroZero

CelsiusCelsius 00 100100 -273-273

FahrenheitFahrenheit 3232 212212 -460-460

KelvinKelvin 273273 373373 00

Absolute ZeroAbsolute Zero

The coldest temperature possible. The coldest temperature possible. All heat has been removed. All heat has been removed.

Freezing/ MeltingFreezing/ Melting

Freezing point is the Freezing point is the temperature at which a temperature at which a liquid changes to a liquid changes to a solid.solid.

Melting point is the Melting point is the point at which a solid point at which a solid changes to a liquidchanges to a liquid

Boiling PointBoiling Point

Point when liquid Point when liquid changes to a gas.changes to a gas.

Boiling and Freezing pointsBoiling and Freezing points

Are different for different Are different for different substancessubstances..

EvaporationEvaporation

This occurs on the This occurs on the surface of a liquid. surface of a liquid. The atoms of the liquid The atoms of the liquid on the surface gain on the surface gain enough heat energy to enough heat energy to escape as a gas.escape as a gas.

BoilingBoiling

When a liquid boils the bubbles form When a liquid boils the bubbles form throughout the liquid and rise out of the throughout the liquid and rise out of the liquid.liquid.

What is conductionWhat is conduction

Conduction is the Conduction is the process of heat process of heat transfer. transfer.

Transfer of energy Transfer of energy through matter in through matter in which energy moves which energy moves from particle to from particle to particle.particle.

Conductors and InsulatorsConductors and Insulators

Metals are good conductors of heat.Metals are good conductors of heat. A conductor is a material that allows heat to A conductor is a material that allows heat to

move through it easily. move through it easily. Insulators do not conduct heat well.Insulators do not conduct heat well. Examples are wood, plastic, straw and Examples are wood, plastic, straw and

paper. paper.

ConvectionConvection

Convection is the Convection is the transfer of energy by transfer of energy by the bulk movement of the bulk movement of matter in which matter in which particles move from particles move from place to place in a place to place in a fluid, carrying the fluid, carrying the energy with them.energy with them.

Convection CurrentConvection Current

Water boils at the bottom of a heated pot, Water boils at the bottom of a heated pot, its particles move faster, and they also move its particles move faster, and they also move farther apart. As a result heated water farther apart. As a result heated water becomes less dense. The heated water becomes less dense. The heated water rises and the surrounding cooler water flows rises and the surrounding cooler water flows into its place. This flow creates a circular into its place. This flow creates a circular motion called the convection current.motion called the convection current.

RadiationRadiation

Radiation is the Radiation is the transfertransfer of energy by of energy by electromagnetic electromagnetic waves. waves.

Radiation does not Radiation does not require matter to require matter to transfer thermal transfer thermal energyenergy

Solar RadiationSolar Radiation

Process by which energy from the sun can Process by which energy from the sun can be transported.be transported.

Sunlight Sunlight

Made up of infrared – heatMade up of infrared – heat Visible light – what we seeVisible light – what we see Ultraviolet radiation.Ultraviolet radiation.

Ultraviolet radiation is harmful to your body. Ultraviolet radiation is harmful to your body.

SPFSPF

Sun Protection Factor is the is how Sun Protection Factor is the is how sunscreens are rated. The SPF ratings sunscreens are rated. The SPF ratings indicate the amount of protection that a indicate the amount of protection that a sunscreen will provide.sunscreen will provide.

Sunlight DangersSunlight Dangers

Eye diseaseEye disease Weaken bodies ability to fight some virusesWeaken bodies ability to fight some viruses Skin cancersSkin cancers