Healthy Screen Time Tips

Key Points from Teacher Melvin

1. Sit Properly

   • Ensure your back is touching the chair backrest.

2. Change Position Regularly

   • Alternate sitting on couch, chair, or floor during long viewing periods.

3. Maintain Dim Lighting

   • Use dim light rather than strong or no lighting to prevent eye damage.

4. Stretch During Breaks

   • Utilize commercial breaks for gentle stretches and to walk around.

5. Avoid Watching TV in Bed

   • Prevents neck and back pain.

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Introduction to Module 2: Plate Boundaries

Review of Module 1

• Completed four episodes on:
  • Plate tectonics
  • Earthquake epicenters
  • Active volcanoes
  • Major mountain ranges

Jigsaw Puzzle Activity

• Images Represented:
  • Mount Everest
  • Mariana Trench
  • Great Rift Valley

Earth's Structure

• Earth’s outer surface consists of tectonic plates at plate boundaries.
• Types of Crust:
  • Continental Crust: Thicker, less dense
  • Oceanic Crust: Thinner, denser

Plate Boundaries

• Movement of Plates:
  • Caused by convection currents in the Earth's interior.

Types of Plate Boundaries

1. Divergent Boundaries

   • Plates move away from each other.
   • Example: Mid-Atlantic Ridge.
   • Forms rift valleys and ocean basins.

2. Convergent Boundaries

   • Plates collide, leading to:
     • Mountain ranges (e.g., Himalayas)
     • Subduction (one plate diving under another).
   • Example: Mariana Trench.

3. Transform Boundaries

   • Plates slide past each other horizontally.
   • Example: San Andreas Fault.

Oreo Cookie Experiment

• Materials Needed: Oreo cookies to illustrate plate movements.
  1. Divergent: Slide upper cookie over filling, simulating plates moving apart.
  2. Convergent: Push cookies toward each other to show collision.
  3. Transform: Slide cookies laterally to demonstrate lateral movement.

Summary of Plate Movements

• Divergent: Plates move apart, magma rises.
• Convergent: Plates collide, forming mountains or subduction zones.
• Transform: Plates slide past each other causing earthquakes.

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Science Quiz

Questions

1. Convection current causes lithospheric plates to:

   • A) Move slowly but constantly
   • Correct Answer: A

2. Represents a divergent boundary:

   • C) Mid-Atlantic Ridge
   • Correct Answer: C

3. Event when tectonic plates move apart:

   • D) Molten rock escapes from the mantle
   • Correct Answer: D

4. Example of a transform plate boundary:

   • B) San Andreas Fault
   • Correct Answer: B

5. At convergent boundary:

   • B) The older crust is melted by subduction
   • Correct Answer: B

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Conclusion

• Life's uncertainties should be faced with courage.
• Remember: Science is fun for everyone!
• Next episode to continue learning with Teacher Melvin.