Sources and Properties of Light

Prep up:

"Imagine a world with no light – we'd all be bumping into walls! Light helps us see and keeps us safe. 

Fill in the blanks: 

The Sun is a _____ source of light, while a bulb is a _____ source of light!"

What is Light?

Light is a form of energy that helps us see the world around us. It travels in straight lines and can move through some materials, like air, water, and glass. Light makes objects visible to our eyes.

 

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Sources of Light

1. Natural Sources:

• Sun: The main source of light on Earth.

• Stars: Emit their own light, like the Sun.

• Fire: Flames give off light.

• Bioluminescent Organisms: Some animals and plants, like fireflies and jellyfish, produce light naturally.

2. Artificial Sources:

• Electric Bulbs: Produce light using electricity.

• LEDs: Modern energy-efficient light sources.

• Candles and Lamps: Use fire or electricity to emit light.

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Properties of Light

1. Light Travels in a Straight Line

• Light moves in straight paths called rays.

• Example: The beam from a flashlight.

2. Reflection of Light

• Light bounces back when it hits a shiny or smooth surface. This is called reflection.

• Example: You can see your face in a mirror because of reflection.

3. Refraction of Light

• When light passes through materials like water or glass, it bends. This bending is called refraction.

• Example: A pencil looks bent when placed in a glass of water.

4. Absorption of Light

• Some materials absorb light instead of reflecting it. Dark colors absorb more light, while light colors reflect more.

5. Light is Made of Colors

• White light is a mixture of seven colors: Red, Orange, Yellow, Green, Blue, Indigo, Violet (like a rainbow).

• Example: A prism splits white light into these colors.

6. Light Travels Fast

• Light travels at an incredible speed of 300,000 kilometers per second in space.

 Important Terms

1. Luminous Objects: Objects that produce their own light (e.g., Sun, bulb, firefly).

2. Non-Luminous Objects: Objects that do not produce light but reflect it (e.g., Moon, book, table).

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Why is Light Important?

• Light allows us to see things.

• It helps plants grow through photosynthesis.

• Light gives us heat and energy.

Fun Activity: Try shining a flashlight at a mirror and see how the light bounces back!

Quiz

1. What does light travel in?
a) Curves
b) Waves
c) Straight lines
d) Circles

2. Which of the following is NOT a source of light?
a) Sun
b) Fire
c) Moon
d) Candle

3. What happens when light hits a mirror?
a) It absorbs
b) It reflects
c) It disappears
d) It bends

4. What does the retina in our eye do?
a) Sends light to the brain
b) Turns light into messages
c) Makes light
d) Focuses the light

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Practice Worksheets:

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Easy Level Worksheets

Intermediate Level Worksheets

Advance Level Worksheets