Activity 1: Think about a time when you were very hot or cold. Free write about it. Underline your best words and wiggle into a poem! Make it pretty.

Does an ice cube have heat? All matter has heat. Some, just more than others.

What Causes Heat? Heat is caused by vibrating molecules. Heat is defined as the total energy given off by vibrating molecules. Molecules are always vibrating. This means all matter has heat. How hot an object is depends on how fast its molecules vibrate. The faster the molecules vibrate, the hotter the object will be. Eg. Boiling water

The Particle Theory of Matter... (PTM) Remember:  All matter is made up of tiny particles.  These particles are always moving – they have energy. The more energy they have, the faster they move. There is space between all particles.  There are attractive forces between the particles.  The particles of one substance are the same but differ from another substance.

Temperature: The average kinetic energy (energy of movement) of the particles of a substance.

Each color represents a particle of a varying speed. The average of these energies would be the temperature.

ExpansionContraction Increasing the volume of a substance because when the particles are heated, they gain energy, move faster, spread out and take up more space. Decreasing the volume of a substance when the particles are cooled, they lose energy, move slower, move closer together and take up less space.

A Solid A GAS A LIQUID Why do we need to be concerned with expansion and contraction in the above pictures?

Changes of State Blue = add heatRed = lose heat Deposition

Graphing changes of sta te (a Heating Curve)

Changes of state and the PTM 1. Adding heat energy, increases the kinetic energy and therefore the temperature. 2. Decreasing heat energy, decreases the kinetic energy and therefore lowers the temperature.

3. The particles break their attractive forces with their neighbouring particles when kinetic energy is increased.

4. Eventually, the kinetic energy will be great enough to break the attractive forces holding the particles together thereby changing state. The opposite is true if heat energy is decreased.

Heat and Temperature Heat total energy given off by vibrating molecules measured in calories. Temp used to describe the amount of heat felt. measured with a thermometer. always measured in degrees (Celsius, Kelvin or Fahrenheit)

Heat Heat depends on 2 things: 1) How fast the molecules move 2) How many molecules vibrate (Size does affect the amount of heat) If you have a large object and a small object with the same temperature, which one will have more heat? The larger object will have more molecules, so it will have more heat.

Measuring Temperatures 1. Galileo’s Air Thermoscope: As the air heats, the liquids drops and rises when air is cooled. Early Thermoscopes...

2. Early Liquid Thermometer: Liquid rising up the tube shows the temperature is rising.

Temperature Scales Scales are necessary for temperatures to be accurate and comparable.

3 commonly used scales are: 1. Fahrenheit 2. Celsius 3. Kelvin

Fahrenheit Developed by Daniel Fahrenheit The first to be widely used

Celsius Developed by Anders Celsius. Based on the freezing and boiling points of water.

Kelvin  Developed by William Thomson (Lord Kelvin)  Scale starts at the coldest temperature possible – absolute zero (-273 ˚ C)

Comparison chart using various temperature scales KelvinCelsiusFahrenheit Water boils373.16K100°C212°F Water freezes K0°C32°F Absolute zero 0K °C-459.7°F

Converting between Celsius and Fahrenheit Fahrenheit to Celsius(°F - 32) x 5 / 9 = °C Celsius to Fahrenheit(°C × 9 / 5 ) + 32 = °F

Converting between Celsius and Kelvin Celsius to Kelvin: T (K) = T (°C) Convert 10 degrees Celsius to Kelvin: 10°C = K Kelvin to Celsius: T (°C) = T (K) Convert 300 Kelvin to degrees Celsius: T (°C) = 300K = °C

Measuring Devices 1. The Liquid-in-glass Thermometer The lab thermometer contains colored alcohol rather than mercury for safety.

2. The Thermocouple Made of two wires of different metals. A temperature difference causes a current to flow through the wires. This current is measured by a meter.

Can measure higher temperatures than typical thermometers.

3. The Resistance Thermometer (digital thermometers)

4. Bimetallic Strip (thermostat)  Made of two different metals fused together.  These metals expand and contract at different rates causing the strip to bend when heated.

Thermostat

Heating and Cooling a Bimetallic Strip

5. Infrared Thermometer (thermogram)  Converts infrared radiation into colors that can interpret a temperature difference.

Can be used to measure heat loss in your home

Questions to Complete for next class Due Wednesday June 1 Complete the conversion worksheet on the 3 types of temperature scales (Celsius, Fahrenheit, and Kelvin. Read pages 80 and 81 in your textbook and complete questions 1,2 and 3. This will be due Wednesday at the beginning of class.

Radiation Conduction Convection

Picture a Hot Light Bulb Put your hand over the bulb. What happens? Why? Your skin is receiving thermal energy. Heat always transfers from a hot object to a cold object.

Energy Sources The light bulb is an energy source. An energy source is an object or material that can transfer its energy to other objects. 3 ways in which energy can be transferred are: Radiation, Conduction, Convection

3 Types of Heat Transfer

Radiation Transfers Energy Radiation is the transfer of energy in a special form of wave. Energy transferred in this way is called radiant energy and is carried by electromagnetic radiation (EMR).

There are no particles involved. The waves can travel in a vacuum.

Types of Electromagnetic Waves

Characteristics All types of radiant energy share these characteristics: 1) They behave like waves 2) The can be absorbed and reflected 3) They travel at km/s

Comparing Surfaces SurfaceAbility to absorb Ability to radiate Ability to reflect Light colored Dark colored Shiny texture Dull texture Fill in blanks with “Better” or “Worse” Worse Better

Conducting Energy Through Solids In solids, are particles close together? Thermal energy can be passed directly from one particle to the next. Thermal conduction occurs when the particles in an object vibrate in place but collide with neighbouring particles passing kinetic energy to them. The particles do not leave their original position. Conduction occurs in most solids.

Conducting Energy Through Solids Particles near the heat source absorb energy from it and begin moving faster

Conducting Energy Through Solids The fast moving particles bump into their neighbors and increase their energy/motion

Conducting Energy Through Solids In this way, thermal energy is transferred throughout the entire object

Copper Bottom Stainless Steel Sides

Ice Packs

Convection Occurs when warm fluids move from one place to another. Occurs in liquids and gases.

Convection- Energy on the Move D A- Warmed air particles expand B- Less dense, warmer air rises C- The rising air cools and contracts D- The cool, denser air sinks E- The cool air moves in to replace the rising warm air

When air warms, the particles gain energy, spread out, become less dense and rise. As it cools, the particles lose energy, get closer together, become more dense and sink. Convection Currents

The three types of heat transfer, conduction, convection and radiation, can occur at the same time. For Example...

Home Heating Technologies Open Fireplace Radiant heat from the fire and convection currents in the air spread the heat.

2. Electric Heaters

3. Oil Furnace:  Air is drawn into the furnace and heated and fans would blow the warm air through the ducts into the rooms.  Water carried in a system of pipes can be used instead of air. (Hot water radiation)

Forced-air furnace

Hot Water Radiation

4. Air to Air Heat Pump Can be used to cool the home in the summer and heat the home in the winter. Heat is exchanged with the outside air.

5. Geothermal: Heat is exchanged with the ground. In the summer, heat is pumped into the ground and in winter it is pumped up from the ground.

Geothermal

6. Solar Converts light energy to electrical energy.

Solar Panels

Core STSE “Heat Pumps: An Alternative Way to Heat Homes”

Conductors vs. Insulators Conductors  Allow heat transfer  Ex. Metal (some metal are better than others) Insulators  “Prevents” heat transfer  Ex. Wood, plastic

Uses of Conductors Cookware Car Radiator

Use of Insulators: Animal Fur Sod

Fibreglass Thermos

The vacuum layer has no particles which prevents heat transfer. Note: It is impossible to create a perfect vacuum.

Specific Heat Capacity The amount of heat needed to raise the temperature of 1.00 g of the substance by 1.00 ˚C. Used to measure the amount of heat transfer.

Different materials have different capacities for storing heat. This depends on:  Molecular structure  Phase  Molecular mass  Shape  Surface area

Specific Heat Capacities

Specific Heat Capacity An Example...

Temperature Heat & technology With a partner, list as many technologies that deal with the idea of temperature and heat.