Heat Transfers
Unit 8 I
Do Now:
• What materials are best for keeping you warm?
Heat vs. Temperature
• Temperature – how hot or cold something is
• Measured with a thermometer
• Usually measured in Celsius
• Heat – a form of energy
• Measured in joules
• Also called thermal energy
• https://phet.colorado.edu/en/simulation/energy-forms-and-changes
Heat Transfers
• Atoms want to be happy 
• If you combine two materials of different temperatures, the atoms
will transfer heat to reach a happy place
Activity:
• Match the temperatures to the object.
• Cut out, match and glue into your book.
Do Now:
• Pick up a worksheet from the table in the front and complete it.
Conductors and Insulators
• Conductor – lets energy flow through it
• Conduction – when energy travels through solids
• Example: Saucepans
• Insulator – holds heat energy (hot or cold)
• Example: Thermos
Conductor or Insulator?
Heating a Solid:
• What happens when you heat a solid?
Before the Melting Point:
• Particles will get excited (vibrate):
• Solid, especially metals will expand
• Contracts: gets smaller
Do Now:
• Review the results from your experiment. How does heat and volume
effect the change in temperature after the final liquids are combined?
Homework Review
• From page 132
Changing States of Matter:
Phase Change Diagram
Activity:
• Illustrate a change in matter for water. Label the
changes and create a change diagram
• Prize to the best poster 
Do Now:
• What do you think of when you hear the word “radiation?”
• What is radiation?
Radiation
• Transfer of thermal energy by waves
• Infrared Radiation – Energy from the Sun
• All hot things emit radiation
• When radiation hits things it can be
absorbed or reflected
Natural or Background Radiation
• Radon, a radioactive gas from uranium found in soil
• Radioactive Potassium in our food and water;
• Uranium, Radium, and Thorium in the Earth's crust;
• And from Cosmic Rays and the Sun.
Man-made radiation sources
• tobacco,
• television,
• medical x-rays,
• smoke detectors,
• lantern mantles,
• nuclear medicine,
• building materials
Calculate Your Radiation Exposure
Do Now:
Page 128 – Answer Question 3
Measuring Radiation
• A Geiger counter has a negatively
charged Cu tube with a positively
charged wire running through it.
• The tube is filled with gas at low
pressure.
• Radiation knocks electrons off the
gas which are attracted to the wire
producing a current.
Measuring Radiation
• https://www.youtube.com/watch?v=TRL7o2kPqw0
Infrared Images
• Pictures that show heat
• What is this useful for?
Ionizing vs. Non-ionizing
Wavelengths
Buildings
Or 3 Foot ball fields
Humans Honey
Bee
Pen
Head
Coin
(side)
Molecule
Atom
Dangerous Particles
• Alpha radiation is not as dangerous because it is unlikely to reach
living cells inside the body.
• Beta is slightly more dangerous, as it can penetrate the body and
• Gamma radiation is the most dangerous because it can penetrate the
skin and damage the cells inside
Create Your Own EM Spectrum
• Fold a piece of paper into 8 equal pieces, then cut along the center
• I will show you how to do it
• Front page should include a title and your name
• Each page should have 1 part of the electromagnetic spectrum
• Include examples for each
Do Now:
• Visible Light is the only portion of the electromagnetic spectrum we
can see. Arrange the following colors in order of largest wavelength
to the smallest:
•
•
•
•
•
•
•
Orange
Indigo
Yellow
Red
Blue
Green
Violet
Convection Current
• What happens when you heat a liquid?
• Add energy
• Liquid will boil
Can the entire liquid be at the same
temperature?
Convection Current
• Remember learning hot air rises?
• Convection Current – movement created by heating a liquid
• Hot water rises
• Cooler water sinks
Where can we see convection currents at
work?
Convection Currents in the Earth
• Convection currents can
move the Earth’s plates
• Solid rocks constantly
heating and cooling cause
plates to move
• What are the results?
• https://www.youtube.com/watch?v=jkKlGXG4lG8
Activity:
• Wednesday we will complete a lab. We will be heating water and
watching the convection current flow with food coloring.
• Complete the worksheet by cutting and pasting the statements as you
would expect to see in the lab.
Exit Ticket
• Besides convection currents in the Earth. Describe another
convection current you experience in life.