Investigating Heat and Temperature

Lab Stations:Lab Stations: Lab 3: “Energy on the Move” Pages 23 - 42

Lab 4: “It’s Just a Phase” Pages 43 - 55

Energy on the Move:Energy on the Move:Investigating Energy TransferInvestigating Energy Transfer

Objectives:Objectives: The student will:

Compare and Contrast the transfer of energy by conduction, convection and radiation while providing and explaining common examples of each

Objectives:Objectives: Investigate and understand practical and technological applications of thermal energy

Explain how a coiled thermostat works

Key Terms:Key Terms: Thermal Conductor Thermal Insulator

Thermal Conductor Any substance

that conducts, absorbs energy and increases temperature quickly allowing thermal energy to collect and pass through it

Thermal Insulator Any substance

that does not allow the transfer of thermal energy or impedes thermal energy transfer

Essential Learnings Materials that allow energy to

move through them are called thermal conductors

Metals generally conduct thermal energy well but at different rates Depending on the metal’s density

Essential Learnings Convection is the transfer of

thermal energy within fluids and gases (air is considered a fluid for this purpose) by the movement of molecules from place to place.

Molecules carry the energy with them

Essential Learnings The circular motion of fluids

(related to temperature) due to density differences is known as convection currents

Essential Learnings Radiation is the transmission of

energy in the form of electromagnetic waves

Radiation travels in transverse waves

This type of energy does not require matter to transfer

P4 P4 It’s Just a Phase:It’s Just a Phase:Investigating Phase Investigating Phase ChangesChanges

Objectives

The student will illustrate and explain the results of the addition and subtraction of thermal energy on the motion of molecules

Objectives The student will:

Create and examine a temperature graph of phase changes

Label each phase change Determine Freezing, melting, condensation and boiling points from a graph

Key Terms:Key Terms: Phase Change Freezing Point Melting Point Boiling Point Vaporization Condensation

Phase Change When matter

transforms from a solid to a liquid or to a gas Ice Water

Water Vapor

Freezing Point The

temperature or point when a liquid becomes a solid

Water Ice

Melting Point The

temperature or point when a solid substance turns into a liquid

Ice water

Freezing & Melting Melting and

Freezing points are actually the same temperature!

Boiling Point The maximum

temperature at which a liquid can remain in liquid form before turning to vapor or gas

Vaporization When a liquid

becomes a gas Water Steam

(water vapor)

Condensation Point The

temperature or point when vapor becomes a liquid

Vapor Cloud rain

Boiling & Condensation Boiling and

Condensation points are actually the same temperature!

Essential Learnings: Vaporization is the change of

state from liquid to gas Condensation is the change

of state from gas to liquid Both processes take place at

the boiling point of a substance

Essential Learnings: The melting/freezing point and

boiling/condensing point for a pure substance are characteristic properties Pure water melts/freezes at 0oC, and it

boils/vaporizes at 100oC at 1 atmosphere air pressure (sea level)

Higher above sea level

Essential Learnings: As thermal energy is added to a

system the temperature does not always increase Temperature will not increase

during a phase change This is because the energy is needed

to break down the physical forces that bond the molecules to one another

Essential Learnings: Phase changes are indicated by

a horizontal or flat line with no slope, called a plateau Water has two plateaus during

heating One at freezing(melting point) One at vaporization (boiling point)

Essential Learnings: All solids are “Frozen” Freezing is not necessarily “cold’ The freezing point is the temperature

at which a liquid becomes a solid For a pure substance freezing point

is a characteristic property and is independent of the amount of the substance

Essential Learnings: A substances’ cooling graph shows a

plateau at condensation point and the freezing point

The temperature will remain constant during the entire phase change

After the phase change cooling continues until thermal equilibrium is reached