Grade 8 Quick Quiz: Light, Albedo, Measurement, and the Water Cycle

            📚 Science
                            🎓 Grade 8
                                

Learning Objectives

Explain that white light contains all visible colors, objects appear colored due to selective absorption and reflection, and darkness is the absence of light.
Define albedo and predict that different surfaces reflect and absorb different amounts of light.
Describe why SI units are used in science and convert US fluid ounces to milliliters using a provided conversion factor.
Match key water cycle process terms to their definitions.
Recognize that most of Earth's water is not directly usable for drinking, agriculture, or industry.

            Progress
            6 sections
        

1
Instructions

Use the notes and diagrams below as needed. Answer each question by choosing the best option.

2
Question 1

White Light Through a Prism (ROYGBIV)

  White light through a prism (ROYGBIV)

  white light
  
  prism

    R
    O
    Y
    G
    B
    I
    V
  
  Objects look colored because they reflect some wavelengths and absorb others.
            
A beam labeled white light enters a triangular prism and exits as separated colored rays labeled R O Y G B I V....

Question 1

A prism can split white light into the visible spectrum (ROYGBIV). Which statement is most accurate? (See Diagram C-002 if helpful.)

White light is only one color, and a prism adds the other colors.
White light contains many colors; an object looks red because it reflects red light and absorbs most other colors; darkness is the absence of light.
Objects make their color by emitting all colors equally, even in the dark.
Darkness is a type of black light that objects reflect.

3
Question 2

Albedo is a measure of how much light a surface reflects. High albedo means lots of reflection. Low albedo means more absorption and less reflection.

Albedo: Snow vs Dark Surface

  Albedo: snow reflects more light

  Sun

  Snow (high albedo)

  Dark surface (low albedo)

  eyes

  reflected light
            
Sun rays strike snow and a dark surface. The snow reflects many rays upward while the dark surface reflects fewer, indicating higher and lower albedo....

Question 2

Albedo is a measure of how much light a surface reflects. Fresh snow can cause snow blindness on a sunny day. Which explanation best connects snow blindness to albedo? (See C-003 and Diagram C-004 if helpful.)

Snow has low albedo, so it absorbs light and makes the air brighter.
Snow has high albedo, so it reflects a large amount of sunlight into your eyes.
Snow produces its own light, so it shines brighter than the Sun.
Snow has no albedo, so it makes light disappear.

4
Question 3

Imperial (US customary) units are used in everyday life in some countries (inches, feet, fluid ounces). SI units are the standard units used in science worldwide (meters, liters, grams). Scientists use SI because it is consistent, shared internationally, and based on powers of 10, which makes conversions and calculations simpler and less error-prone.

Conversion Chart: Fluid Ounces to Milliliters

  Conversion chart

  US customary
  SI

  1 fl oz
  29.6 mL

  Value rounded for easier math.
            
A simple chart showing 1 US fluid ounce equals 29.6 milliliters, rounded....

Question 3

Imperial (US customary) units are common in daily life in some places, but science uses SI units because they are consistent worldwide and easier to calculate with. Use the conversion chart: 1 US fluid ounce (fl oz) = 29.6 milliliters (mL) (rounded). (See C-005 and Diagram C-006 if helpful.)

A bottle holds 10 US fluid ounces. About how many milliliters is that?

2.96 mL
29.6 mL
296 mL
2960 mL

5
Question 4

Water Cycle Processes (Overview)

  Water cycle processes (overview)

  Ocean / lake

  Land

  Clouds

  Plant

  Evaporation

  Transpiration

  Condensation

  Precipitation

  Infiltration

  Runoff
            
A simplified water cycle diagram labeling evaporation, transpiration, condensation, precipitation, infiltration, and runoff with arrows between ocean, land, plants, and clouds....

Question 4

Match each water cycle term to its correct definition. (See Diagram C-007 if helpful.)

EVAPORATION

TRANSPIRATION

CONDENSATION

PRECIPITATION

INFILTRATION

RUNOFF

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Question 5

                💡
                Earth's water (big idea)            

Most of Earth's water is saltwater. Only a small fraction is freshwater, and much of that freshwater is locked in ice or stored underground.

Question 5

The vast majority of Earth's water is NOT usable for drinking, agriculture, or industry. (See Callout C-008 if helpful.)