2. Chapter Menu Lesson 1: What is light? Lesson 2: Light and Matter
Lesson 3: Using Lenses
Lesson 4: The Eye and Vision
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3. 11.1 What is light? wavelength frequency medium
electromagnetic spectrum

4. Light Transfers Energy
11.1 What is light?
Light Transfers Energy
Similar to water waves, light waves also carry energy from place to place.

5. 11.1 What is light?
Parts of a Wave
The distance between any two crests of any two troughs is the wavelength.

6. Frequency and Wavelength
11.1 What is light?
Frequency and Wavelength
The frequency of a wave is the number of wavelengths that pass a given point in one second.
As the frequency of a wave increases, wavelength decreases.

7. Electromagnetic Waves
11.1 What is light?
Electromagnetic Waves
The substance through which a wave moves is called the medium.
Light is an electromagnetic wave, which is a type of wave that can travel in empty space as well as in matter.

8. 11.1 What is light?
A Range of Wavelengths
The electromagnetic spectrum includes all electromagnetic waves.
It is arranged in order, from those with the longest wavelengths to those with the shortest wavelengths.
Frequency increases as wavelength decreases, and is arranged in order of increasing frequency.

9. 11.1 What is light?
Visible Light
The visible light spectrum is the range of electromagnetic waves human eyes can detect.
Visible light wavelengths are measured in nanometers (nm).
The wavelengths range from 700 nm to 400 nm.

10. 11.1 What is light?
Visible Light (cont.)

11. What is the amplitude of a wave? A distance from crest to crest
11.1 What is light? A B C D
What is the amplitude of a wave?
A distance from crest to crest
B distance from crest to trough
C distance from crest to resting position
D wavelength x frequency
Lesson 1 Review

12. A the distance from crest to trough
11.1 What is light? A B C D
What is a wavelength?
A the distance from crest to trough
B the distance from crest to the rest position
C the distance from crest to crest
D the opposite of frequency
Lesson 1 Review

13. What is the term for the substance through which a wave moves?
11.1 What is light? A B C D
What is the term for the substance through which a wave moves?
A medium
B substrate
C water
D vacuum
Lesson 1 Review

14. End of Lesson 1

15. 11.2 Light and Matter absorption transmission scattering refraction
law of reflection

16. The Interaction of Light and Matter
When light rays hit matter, they can be absorbed, reflected, or pass through the matter.
All electromagnetic waves, including light, transfer energy from one place to another.

17. 11.2 Light and Matter
Absorption of Light
Absorption occurs when light rays hit a material, and some of the rays’ energy is transferred to the atoms in the material.
The transfer of energy can cause the temperature of the material to increase.

18. 11.2 Light and Matter
Transmission of Light
Transmission occurs when light waves strike a material and pass through it, such as with glass.
Whether the light waves are transmitted or absorbed depends on the wavelength of the light waves.

19. 11.2 Light and Matter
Scattering of Light
Scattering occurs when a material causes light waves traveling in one direction to travel in all directions.

20. Opaque, Transparent, and Translucent Materials
11.2 Light and Matter
Opaque, Transparent, and Translucent Materials
The three candleholders are made of different materials that absorb, transmit, and scatter light in different ways.

21. The Speed of Light in Different Materials
11.2 Light and Matter
The Speed of Light in Different Materials
No object or wave can move faster than the speed of light in empty space.
When light waves travel in matter, they move more slowly.

22. 11.2 Light and Matter
Refraction
Refraction occurs when a light ray changes direction when it moves from one material to another.

23. Refraction and Speed Changes
11.2 Light and Matter
Refraction and Speed Changes
Light waves change direction—refract—when they change speed moving from one medium to another.
Bending Light

24. 11.2 Light and Matter
The Visible Spectrum
White light is a combination of all light waves in the visible light spectrum.
Almost any color of light can be made by mixing the three primary colors—red, green, and blue—in different amounts.

25. The Visible Spectrum (cont.)
11.2 Light and Matter
11.2 Light and Matter
The Visible Spectrum (cont.)

26. 11.2 Light and Matter
Reflection
According to the law of reflection, when a light ray is reflected from a surface, the angle of incidence equals the angle of reflection.

27. Regular and Diffuse Reflection
11.2 Light and Matter
Regular and Diffuse Reflection
Light ray reflected from an uneven surface hits a spot in the surface that is at a slightly different angle, causing the rays to go in many different directions.
Diffuse reflection is the reflection of light rays from a rough surface.

28. Regular and Diffuse Reflection (cont.)
11.2 Light and Matter
Regular and Diffuse Reflection (cont.)
The smooth surface of a mirror reflects parallel light rays so that they remain parallel.
This is called regular reflection.

29. 11.2 Light and Matter
Reflection and Color
As white light strikes and object, some of the light is absorbed and some is reflected.
The reflected light enters your eyes and causes you to see the object.
Color

30. 11.2 Light and Matter A B C D
What is the term for the process of transferring light energy to the molecules in a material?
A transmission
B absorption
C scattering
D refraction
Lesson 2 Review

31. Which of the following does light travel fastest through?
11.2 Light and Matter A B C D
Which of the following does light travel fastest through?
A transparent objects
B empty space
C air
D water
Lesson 2 Review

32. Why does an object appear to be blue? A it absorbs the blue wavelength
11.2 Light and Matter A B C D
Why does an object appear to be blue?
A it absorbs the blue wavelength
B it scatters the blue wavelength
C it reflects all the other colors except blue
D it absorbs all the wavelengths except blue
Lesson 2 Review

33. End of Lesson 2

34. 11.3 Using Lenses
lens
convex lens
focal point
focal length

35. 11.3 Using Lenses
What is a convex lens?
A lens is a transparent object with at least one curved side that causes light waves to bend.
A convex lens is a lens that bulges outward.
Convex lens: parallel light rays are bent so they come together, or converge
Concave lens: parallel light rays spread apart, or diverge

36. What is a convex lens? (cont.)
11.3 Using Lenses
What is a convex lens? (cont.)
A concave lens is thinner in the middle than at the edges.

37. Light’s Path Through a Convex Lens
11.3 Using Lenses
Light’s Path Through a Convex Lens
A light ray bends when it slows down moving from air into the lens.
The light ray bends again when it speeds up moving from the lens back into the air.

38. Focal Point and Focal Length
11.3 Using Lenses
Focal Point and Focal Length
The focal point is the point where all of the beams of light converge.
In a convex lens, all light rays traveling parallel to the optical axis are bent so that they pass through the focal point.

39. Focal Point and Focal Length (cont.)
11.3 Using Lenses
Focal Point and Focal Length (cont.)
The focal length is the distance from the center of the lens to the focal points.

40. Image Formation by a Convex Lens
11.3 Using Lenses
Image Formation by a Convex Lens
The image formed by a convex lens depends on the position of an object relative to the focal point.

41. 11.3 Using Lenses
Optical Instruments
An optical instrument uses lenses to focus light and create useful images.
Different optical instruments do this by combining lenses in various ways.
Types of optical instruments
Cameras
Telescopes
Microscopes

42. 11.3 Using Lenses
Cameras
A camera is focused by moving various lenses back and forth until a sharp image is formed.
The image is smaller than the object and is upside down.
To take a picture, the shutter opens so that light enters the camera, and film or an electronic sensor is exposed.

43. 11.3 Using Lenses
Cameras (cont.)
To control the amount of light that reaches the film or light sensor, cameras have a diaphragm or an aperture.

44. 11.3 Using Lenses
Telescopes
As an object gets farther away, less of the light from the object enters the openings in your eyes.
A telescope is an optical instrument that makes far-away objects seem closer.
There are two basic types of telescopes—refracting and reflecting.

45. Refracting Telescopes
11.3 Using Lenses
Refracting Telescopes
The objective lens in a refracting telescope is much larger than the opening in a human eye.
Much more light from a distant object enters the objective lens than would enter an eye.

46. Reflecting Telescopes
11.3 Using Lenses
Reflecting Telescopes
An image of a distant object is formed inside the telescope tube when light rays are reflected from the curved surface of a mirror.
The largest telescopes are reflecting telescopes.

47. 11.3 Using Lenses
Microscopes
The eyepiece lens of a microscope is positioned so it is closer to the image than one focal length.
This makes the image enlarged by the objective lens even larger.

48. C two focal lengths from the lens D in the center of the lens
11.3 Using Lenses A B C D
Where do all the beams of light passing through a convex lens converge?
A focal point
B optical axis
C two focal lengths from the lens
D in the center of the lens
Lesson 3 Review

49. What happens to light when it moves from air into a convex lens?
11.3 Using Lenses A B C D
What happens to light when it moves from air into a convex lens?
A it is reflected
B it is scattered
C it slows down
D it speeds up
Lesson 3 Review

50. A refracting telescope B reflecting telescope C camera D microscope
11.3 Using Lenses A B C D
Which uses a curved mirror to form an image that is magnified by an eyepiece lens?
A refracting telescope
B reflecting telescope
C camera
D microscope
Lesson 3 Review

51. End of Lesson 3