Leary’s Brook Jr. High Science Department

Science 8 - Unit 3: Optics Student Outline

Chp 4: Properties of Light Name: ______

1.  History of Light

a.  Provide examples of ideas and theories of light used in the past to explain observed properties. (Pythagoras, Michelson) (132-134)

b.  Compare the Speed of Light vs. Sound using thunder and lightning as an example. (135-136)

c.  Provide examples of how scientific knowledge of light resulted in the development of early technologies. (Telescope, Microscope) (133-134)

2.  Properties of Visible Light

a.  Define Light as a form of energy that can be detected by the human eye.

b.  Identify and describe various Properties of Light (not in text as listed) (148-152 & 173-179)

i. travels in a straight line (rectilinear propagation) e.g. shadow formation

ii.  reflects (reflection) e.g. mirrors (specular) and dust (diffuse)

iii.  refracts (refraction) e.g. bent stick effect

iv.  Disperses (dispersion) e.g. formation of a rainbow as light separates into its constituent colors.

v.  travels through a vacuum (does not require a medium) e.g. light from sun and stars reaching earth through space

vi.  travels to different degrees through transparent, translucent and opaque materials e.g. window pane, frosted window

c.  Define visible light spectrum (149-152)

i.  Observe dispersion with a Prism

ii. List constituent colours of visible spectrum in order of degree of refraction. (ROY G BIV)

d.  Define frequency and wavelength. (139-140)

i.  Relate colours to wavelength.

ii. Describe inverse relationship between frequency and wavelength.

3.  Electromagnetic Radiation and Spectrum

a.  Differentiate between visible light spectrum and electromagnetic spectrum. (157-158)

b.  Describe wavelength, frequency and energy, and provide examples of, the electromagnetic spectrum (156-164)

i. radio waves (telecommunications)

ii.  microwaves (cooking food)

iii.  infrared (motion sensors)

iv.  visible light

v.  ultraviolet (sun tanning)

vi.  x-rays (medical detection)

c.  Describe positive and negative effects of radiation. (158-164)

Radiation Type / Positive Effect / Negative Effect
X-Rays / Medical Scanning / Over exposure can lead to cancer
Ultraviolet / Treat jaundice in babies / Skin Cancer
Radio Waves / Communications / Uncertain of long term exposure effects

Terms to Know:

Pythagoras / microscope / telescope / rectilinear propagation / specular reflection
Michelson / diffuse reflection / refraction / reflection / dispersion
vacuum / transparent / translucent / opaque / medium
light / visible light spectrum / prism / constituent colours / inverse relationship
frequency / wavelength / electromagnetic spectrum / radio waves / microwaves
infrared / ultraviolet / x-rays

Chp 4 Quiz


Leary’s Brook Jr. High Science Department

Science 8 - Unit 3: Optics Student Outline

Chp 5: Reflection Name: ______

4.  Properties of Reflection

a.  Differentiate between specular and diffuse reflection. (176-177)

b.  Describe Reflection (178) Define:

i. incident light ray

ii.  reflected light ray

iii.  normal

iv.  angle of incidence

v.  angle of reflection

c.  State the Law of Reflection (178)

(Note: P. 179-185 will be included with Chp 6 “Refraction”)

5.  Ray Diagrams
a. Plane Mirrors (189-191)

i. Lab (core) – Law of Reflection in Plane Mirrors (192-193+lab sheet)

ii. Use SPOT (size, position, orientation, type) to describe image properties. (190)

b.  Concave Mirrors (inside of metal spoon) (197-203)

i.  Define focal point, focal length and the principle axis.

ii.  Lab (core) – Locate focal point of a concave mirror.

iii.  Construct ray diagrams to describe the image properties (SPOT) in concave mirrors (object between focal point and mirror • object between focal point and 2x focal length • object beyond 2x focal length)

c.  Convex Mirrors (safety mirror on bus) (204-206)

i.  Lab - Locate focal point of a convex mirror.

ii. Construct ray diagrams to describe the image properties (SPOT) in convex mirrors.

·  Mirrors assignment – Ray Diagrams

6.  Optical devices using mirrors.(203, 206)

i.  Review different types of optical devices (periscope)

ii. Design and construct an optical device to solve a problem. (256)

Terms to Know:

Reflection / specular / diffuse / Incident ray / Reflected Ray
Normal / Angle of Incidence / Angle of Reflection / Law of Reflection / Plane Mirror
SPOT / Concave Mirror / Convex Mirror / Focal Point / Focal Length
Principle Axis / Ray Diagram / Optical Device

Chp 5 Quiz


Leary’s Brook Jr. High Science Department

Science 8 - Unit 2: Optics Student Outline

Chp 6: Refraction Name: ______

7.  Properties of Refraction

a.  Identify examples of refraction (bent stick effect) (179)

b.  Describe how light is refracted (qualitatively) (179)

c.  Define: (180)

i. incident ray

ii.  refracted ray

iii.  angle of incidence

iv.  angle of refraction

d.  Use concept of medium/density to describe how speed of light changes causing refraction. (181)

e.  Angles of Incidence and Refraction

8.  Convex Lenses (magnifying glass, eyeglasses) (217-221)

a.  Define focal length of a lens Describe how three incident rays refract through convex lenses. Include the following incident rays:

(a) Traveling parallel to the principal axis

(b) Traveling through the optical centre

(c) Traveling through the focus

b.  Construct ray diagrams to describe the image properties (SPOT) in a double convex lens, when the object’s distance changes. Include:

(a) Object between focal point and lens

(b) Object between focal point and 2x focal length

(C) Object beyond 2x focal length

9.  Concave Lenses (eyeglasses) (221-223)

a.  Describe how three incident rays refract through concave lenses. Include the following incident rays:

(a) traveling parallel to the principal axis

(b) traveling through the optical centre

(c) traveling through the focus

b.  Construct ray diagrams to describe the image properties (SPOT) in a double concave lens, when the object’s distance changes. Include:

(a) object between focal point and lens

(b) object between focal point and 2x focal length

(C) object beyond 2x focal length

c.  Describe how lenses correct near-sightedness and far-sightedness.(234)

10.  Optical technologies

a.  Describe examples optical technologies. (243-250)

i.  telescopes (refracting and reflecting)

ii. microscopes

b.  Do core STSE “Fibre Optics”

c.  Provide examples related to optics that illustrate that scientific and technological activities take place individually and in group settings.

i.  Galileo – telescope (individual)

ii. Newton – telescope (individual)

iii.  Hubble Telescope (group)

iv.  Laser technologies (group)

Terms to Know:

Refraction / Refracted Ray / Angle of Refraction / Medium / density
Normal / Convex lens / Concave Lens / Nearsighted / Farsighted
Optical technologies / Microscope / Reflecting Telescope / Refracting Telescope / Fibre Optics

Unit Test