Starter quiz
- Which of the following words means ‘reflect light in many directions at once’?
- absorb
- deflect
- scatter ✓
- shine
- transmit
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- A person sees a book. Which of the following statements explains how they see the book?
- Light travels from the person’s eyes to the book.
- Light hits the book and then travels to the person’s eyes. ✓
- The book produces light which travels to the person’s eyes.
- Light travels from the person’s eyes to the book and back again.
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- Which of the following colours is seen when blue and red light of equal brightness enter the eye of a person who has full colour vision?
- cyan
- magenta ✓
- purple
- violet
- yellow
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- Which of the following colours is seen when red and green light of equal brightness enter the eye of a person who has full colour vision?
- brown
- cyan
- magenta
- violet
- yellow ✓
-
- Which of the following are names of types of cells in the retina of the eye?
- cone ✓
- cylinder
- pyramid
- rod ✓
- stick
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- Which of the following are colours that can only be seen when light of more than one colour enters the eye?
- brown ✓
- cyan
- magenta ✓
- red
- yellow
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Exit quiz
- Which of the following statements explains why a black object looks black?
- it makes all colours of light
- it absorbs all colours of light ✓
- it reflects all colours of light
- it reflects most colours of light
- it reflects black light
-
- Which of the following statements explains why a white piece of paper looks white when white light shines on it?
- it absorbs all colours of light
- it absorbs most colours of light
- it makes all colours of light
- it reflects all colours of light ✓
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- Using the RGB model of white light, we can represent white light using only red, green and blue rays. What does each colour of ray represent?
- white light
- a single colour of light
- the whole of the visible colour spectrum
- all of the colours that the human eye can see
- the range of colours that trigger one type of cone cell ✓
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- Why does a white piece of paper look cyan when cyan light shines on it?
- it absorbs the green and blue light and reflects the red light
- it absorbs the green and blue light, and there is no red light
- it reflects the green and blue light and absorbs the red light
- it reflects the green and blue light, and there is no red light ✓
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- Inside a room with no windows, the only light shining is a green light. Which of the following objects in the room look green?
- a blue book
- a green plant ✓
- a magenta pen
- a white wall ✓
- a yellow flower ✓
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- Inside a room with no windows, there is a lamp shining. The light from the lamp looks magenta. Match each object in the room with the colour it appears to be.
- a cyan book⇔blue ✓
- a green plant⇔black ✓
- a magenta ruler⇔magenta ✓
- a red pen⇔red ✓
Worksheet
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Presentation
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Video
Lesson Details
Key learning points
- Colour is detected in the eye by the R, G and B ‘cone cells’ that each detect a range of colours of light.
- The colour of an object in white or coloured light depends on the amounts of R, G and B light it is reflecting.
- White objects reflect all colours of light so look the same colour as the incident light (whether white or coloured).
- The colours of light that an object does not reflect are absorbed. Black objects absorb all colours of light.
- In red/green/blue light, an object will appear red/green/blue if it reflects that colour, and black if it does not.
Common misconception
Colour is the sum of the colour of the object and the colour of light falling on it.
Use coloured lights to show that red coloured objects reflect red light, but not blue or green.
Keywords
Reflect - to hit a surface and ‘bounce’ off
Incident - a word used to describe the incoming light that hits a surface
Scatter - to reflect light in many directions at once
Cone cell - the cells at the back of the eye that detect colour
Absorb - a material that absorbs light / gains energy from light travelling through it, decreasing the amount of light
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