This document discusses heat and light as forms of energy. It explains that temperature tells us how hot an object is, while heat is the amount of thermal energy in an object. Heat is transferred through conduction, convection and radiation. Conduction involves heat transfer through contact, convection involves heat transfer through rising hot air and falling cold air, and radiation involves heat transfer through electromagnetic waves. Light can be reflected, refracted, or absorbed. Reflection occurs when light bounces off a surface, refraction occurs when light bends as it passes through different materials, and absorption occurs when light energy is transformed into heat energy in an object.

2. HEAT AND LIGHT
• ARE BOTH FORMS OF ENERGY

4. TEMPERATURE AND HEAT
• REFER TO DIFFERENT THINGS

5. THE TEMPERATURE OF AN
OBJECT
• TELLS US HOW HOT THE OBJECT IS

7. HEAT IS
• THE AMOUNT OF THERMAL ENERGY
THAT AN OBJECT HAS.

8. Heat

9. The movement of
heat is from…
Hot Cold

10. Heat is transferred
three ways…
Conduction
Convection
Radiation

11. The first form of
heat transfer is…
Conduction

12. Conduction is heat
transferred by contact.
Source: Maybryonline.org

13. Examples…
Mr. Hand's 8th
Grade Science Site
University of Virginia Physics Department

14. What stops heat
transfer?
An Insulator.

15. Examples…

16. The second form
of heat transfer is…
Convection

17. Hot rises, cold falls
creating currents.
“Older Than Dirt” WebQuest Think Energy (UK)

18. Examples of
convection

19. The third form of
heat transfer is…
Radiation

20. Radiation is heat as
an electromagnetic
wave.

21. The wave becomes
heat when it hits an
object.

22. Examples of
radiation

23. WHAT ARE THE EFFECTS OF
THERMAL ENERGY?
• THERMAL ENERGY CAUSES CHANGES
IN THE STATE OF SOME MATERIALS.

24. 1. MELTING
• make or become liquefied by heating.

25. 2.

28. CHEMICAL CHANGES
• THERMAL ENERGY CAN CAUSE
CHEMICAL CHANGES.

29. Light

31. Sources of light…

32. A light source
produces light.

33. What happens when light
hits an object?
The light is reflected off
the object.

34. We see things because of
reflected light.
We see red, because red
light is reflected; blue
because blue is reflected;
white because all light is
reflected.

35. We see ourselves in a mirror
because of reflection.

36. The light that hits an object is
called the angle of incidence.
The light that bounces off the
object is called the angle of
reflection.

37. Angle of incidence =
Angle of reflection
Molecular Expressions

38. When light passes thru
transparent objects (water,
glass, etc.), the light is
refracted (bent).

39. When light passes thru
water, it’s refracted.
http://www.nature.com

40. When light travels thru a
prism, the refraction forms
the spectrum.
DiscoveryEducation Clipart

41. The spectrum is the colors
of the rainbow…
DiscoveryEducation Clipart

42. Red, Orange, Yellow,
Green, Blue, Indigo, and
Violet (ROY G. BIV).
DiscoveryEducation Clipart

43. Three things can happen
when light hits an object.

44. If the object is transparent,
it will pass through it.

45. If the object is opaque, the
light will not pass thru the
object and is reflected.

46. HOW IS LIGHT TRANSFORMED
INTO HEAT?
• WHEN LIGHT ENERGY HITS AND
OBJECT, SOME OF THE ENERGY IS
ABSORBED BY THE OBJECT. THIS
ENERGY MAKES THE MOLECULES OF
THE OBJECT VIBRATE FASTER.
• IF WE TOUCH THE OBJECT, WE FEEL
THIS VIBRATION AS HEAT.