Heat and Heat Technology Chapter 10

What is Temperature? __________- A measure of the average kinetic

energy of the particles in an object. All particles are in _______________ (even if

they don’t appear to be) The faster the particles are moving, the more

____________ they have. The more kinetic energy they have, the

________ the temperature. Temperature measures the _______ kinetic

energy of the object because individual particles are moving at different _______ and have different kinetic energies.

Measuring Temperature Using a thermometer-

As a substance’s temperature ____________, it’s particles move faster and ____________. There is more space between them, and the substance expands.

Temperature is measured in three ways: Fahrenheit – Celsius- Used in __________ community. The

freezing point and boiling point of water is separated into 100 even intervals

Kelvin- ____ is the lowest temperature called

____________ – all molecular motion stops

Measuring Temperature

Temperature Conversion Equations

To convert Use the equation ExampleoC to oF oF = (9/5 x oc) + 32  

See # 1 

oF to oC oC = 5/9 x (oF – 32)  See # 2 

oC to K K = oC + 273   

See # 3

K to oC oC = K – 273   

See # 4

Temperature Conversions Convert 45 oC to oF

Convert 68 oF to oC

Temperature Conversions Convert 45 oC to K

Convert 32 K to oC

More About Thermal Expansion Expansion joints in highway bridges

Bridges heat up and ________ – this can cause the bridge to break so ___________________ are installed.

Hot air balloons When the air inside is heated, it expands

and becomes less ________. The balloon rises.

10.2 What is Heat? TRANSFERRED THERMAL ENERGY

_______- The energy transferred between objects that are at different temperatures. Energy is always transferred from the

_________temperature to the __________temperature.

Stethoscopes “feel” cold because energy is transferred _______ from your back to the stethoscope.

Thermal energy is transferredTotal kinetic energy of the particles that makes up the substance

3 Ways to Transfer Thermal Energy

Thermal Conduction is the transfer of thermal energy from one substance to another substance through _______________.

Thermal Conductor- Substances that can conduct thermal energy very ______. Ex:

Thermal Insulator- Substances that ________ conduct thermal energy well. Ex:

Ways to Transfer Thermal Energy

The transfer of thermal energy by the _____________of

a liquid or a gas. Warm air or liquid rises to the top because it’s less

dense (high energy) At the surface, the warm air/liquid cools, condenses, and sinks back to the bottom.

This cycle is called a convection current

Ways to Transfer Thermal Energy

The transfer of energy by _______________,

such as visible light and infrared waves. This can occur in empty space.

Radiation and the Greenhouse Effect Earth’s atmosphere acts like the

windows of a ________ It allows the sun’s _______________to pass

through it. A greenhouse also traps _______,

keeping the inside warm

Specific Heat ___________-The amount of energy

needed to change the temperature of 1 kg (or g) of the substance by 1°C Refer to table 2. Metal needs less energy to raise the

temperature. Water needs more energy. Heat can’t be measured directly

We need to use a formula.

Specific Heat Calculations

How many joules does it take to heat 20. g of water from 10.0 to 40.0 oC? (Cp (water) = 4.184 J/g oC )

Specific Heat Calculations How much heat is required to heat 75 g

of Iron (Cp = 0.444 J/gCo) from 15.5 to 57.0 oC?

Specific Heat Calculations How many joules does it take to change

the temperature of 15 g of water 25oC? (Cp (water)_ = 4.184 J/g oC )

10.3 Matter and Heat

_______________ – the physical forms in which a substance can exist. The states of matter depend on the _______ of the particles.

Gases = Liquids = Solids =

Changes of State ___________A change of a substance from

one state of matter to _______________. PHYSICAL CHANGE!!! Include: An ice cube that melts and then turns

to a gas can be graphed on a temperature vs. energy graph.

Heat and Chemical Changes

Calorimeter- When one object transfers thermal energy to

another object, the energy ______________ object is ________ by the other object.

________________- food is burned, energy released is transferred to the water, temp change of the water can be measured.

1 Calorie of food = ______J of energy.