Exploring Light Properties

Grade Level

4th Grade

Duration

45 minutes

Class Size

20 students

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Unit Overview

Exploring Lights and Shadows (5 lessons) introduces students to the fundamental properties of light, preparing them for deeper inquiry into light and shadow phenomena.

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Lesson 1: Introduction to Light

Lesson Description

Students will investigate basic properties of light, including identifying light sources, understanding light travels in straight lines, and distinguishing between natural and artificial light. Through hands-on exploration and guided discussion, students will begin to conceptualize how light behaves.

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Learning Objectives

By the end of this lesson, students will be able to:

• Identify and list various sources of light (both natural and artificial).
• Understand that light travels in straight lines until it is blocked or reflected.
• Observe and describe how light behaves in simple settings.

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Common Core State Standards Alignment

Although Common Core standards primarily focus on Math and ELA, this science lesson integrates critical reading, writing, and speaking skills aligned with Common Core to reinforce science content knowledge. Additionally, this lesson supports Next Generation Science Standards (NGSS) which many US districts adopt in science curricula.

Relevant Common Core ELA Standards

• CCSS.ELA-LITERACY.RI.4.1: Refer to details and examples in a text when explaining what the text says explicitly.
• CCSS.ELA-LITERACY.SL.4.1: Engage effectively in a range of collaborative discussions with peers on grade 4 topics and texts.
• CCSS.ELA-LITERACY.W.4.2: Write informative/explanatory texts to examine a topic and convey ideas clearly.

Related NGSS Disciplinary Core Ideas for Science Reference

• PS4.B: Electromagnetic Radiation: Objects can be seen only when illuminated. Light is reflected from surfaces to the eyes.
• PS4.A: Wave Properties: Light travels in straight lines unless it is blocked or reflected.

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Materials Needed

• Flashlights (one per group)
• White paper sheets
• Objects to block light (blocks, books, toys, etc.)
• Chart paper or whiteboard
• Markers
• Student science notebooks
• Large cardboard box with one hole cut out (optional for demonstration)

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Lesson Procedure

1. Engage (5 minutes)

• Activity: Light Brainstorm
  Begin with a quick class discussion. Ask students: What is light? Where do you see light around you?
  Record student ideas on chart paper under two categories: Natural Light (sun, fire) and Artificial Light (flashlights, lamps).
  This activates prior knowledge and sets purpose.

2. Explore (15 minutes)

• Activity: Investigating Light Sources and Paths
  Split students into 5 groups (4 students each).
  Each group receives a flashlight and white paper.
  Ask groups to:
  • Shine the flashlight on the paper and observe what happens.
  • Block light with an object and observe the shadow.
  • Move the flashlight at different angles to see how light changes path or shadow shape.
    Groups record observations in their science notebooks with drawings and short notes.

3. Explain (10 minutes)

• Regroup and discuss findings.
• Guide questions:
  • Where does the light come from?
  • How does light travel when we use the flashlight? (Straight line explanation, demonstrated by beam on paper).
  • What happens when the light is blocked?
• Use the cardboard box with a hole and flashlight to demonstrate how light travels in a straight line creating a focused beam.
• Clarify vocabulary: source, beam, shadow, blocked, reflect.

4. Elaborate (10 minutes)

• Activity: Light Source Sorting Game
  Show pictures or real objects of light sources (sun, bulb, candle, TV screen, firefly, etc.).
  Students work in pairs to sort each into natural vs. artificial categories and justify their choice orally.
• Encourage students to add any new examples and explain why each is a light source.

5. Evaluate (5 minutes)

• Exit Ticket:
  Each student writes or draws in their science notebook:
  1. One natural light source
  2. One artificial light source
  3. Draw a simple diagram showing light traveling in a straight line and what happens when it is blocked by an object.

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Assessment

• Formative assessments during group discussions and notebook entries.
• Evaluate the exit ticket for accuracy and understanding of light sources and basic light travel concepts.

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Differentiation Strategies

• Provide sentence starters or vocabulary cards for writers who need support.
• Use visual aids and real objects to support ELLs and students with learning differences.
• Encourage advanced students to think about why some sources produce more light than others.

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Reflection and Next Steps

• Collect student notebooks to review findings and misconceptions.
• Plan Lesson 2: Investigating Shadows - focus on how light creates shadows and changes their size and shape.

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This lesson leverages hands-on inquiry and collaborative learning to foster scientific thinking, integrated with speaking and writing skills development aligned with Common Core standards. It creates a strong foundation for future exploration of light and shadow in the unit.