Science · Unit 8

Light and Sound

How we see and hear the world

Light and sound get taught together because both travel, both carry information, and both are how you find out about things you are not touching. They are otherwise very different.

The unit covers sources of light, shadows and reflection, colour, how sounds are produced by vibration, and what makes a sound high, low, loud or quiet.

This unit breaks down into 21 short steps and 125 questions, starting at difficulty 1 and building to 3. Below you can see exactly what it covers, how the path is structured, and worked examples with explanations.

Steps: 21
Questions: 125
Difficulty: 1-3

What this unit covers

How Sounds Are Made
Colours and Seeing
Sources of Light
High, Low, Loud and Quiet
Shadows and Reflections

Where this fits

Follows Energy All Around. Physics's Light and Optics and Waves and Sound go considerably deeper.

Where people slip

Most things you see are not light sources. They are reflecting light from something else, which is why a room with the lights off contains exactly the same objects and no visible ones.

How the unit is structured

Light and Sound runs as 21 short steps that unlock in order. 15 are practice rounds and 6 are challenge rounds that pull together everything before them. Questions start at difficulty 1 and climb to 3 as you progress.

Step 1 · easierStep 21 · harder

Challenge rounds

Example questions

30 real questions from this unit, with the answer and the reason behind it, grouped by what they practise. There are 125 in the unit altogether.

Colours and Seeing

Build the sentenceLevel 2
1. Build a true sentence about white light.
Answer: White light is made of many colours
White light is a mix of many colours, which is why it can make a rainbow.
Choose all that applyLevel 2
2. A white shirt looks white because of what it does with light. Pick all that are true.
- It reflects all the colours of lightcorrect
- White is all colours of light togethercorrect
- It sends light back to your eyescorrect
- It makes its own white light
A white shirt reflects all the colours of light back to your eyes; it does not make light of its own.
Fill the blankLevel 2
3. A glass ____ can split white light into a band of rainbow colours.
- prismcorrect
- mirror
- window
- magnet
A prism bends each colour of light by a different amount, spreading them into a rainbow.
Guess the numberLevel 2
4. How many colours are usually counted in a rainbow?
Answer: 7 colours
People usually name seven rainbow colours: red, orange, yellow, green, blue, indigo, and violet.
Match the pairsLevel 2
5. Match each thing to the colour we usually see it as.
Answer: Grass = Green; A banana = Yellow; A ripe tomato = Red; A clear daytime sky = Blue
We see each object as the colour of light it reflects back to our eyes.
Fact or fibLevel 3
6. A rainbow forms because raindrops bend and split sunlight into its colours.
Answer: True
Each raindrop acts like a tiny prism, splitting white sunlight into a band of colours.

High, Low, Loud and Quiet

Choose all that applyLevel 2
7. Which of these would make a guitar string play a HIGHER note? Pick all that apply.
- Making the string tightercorrect
- Using a thinner stringcorrect
- Making the string shortercorrect
- Making the string looser
Tighter, thinner, and shorter strings vibrate faster, giving a higher pitch.
Fact or fibLevel 2
8. A tiny bird's chirp is a high-pitched sound.
Answer: True
Small, fast vibrations make high-pitched sounds like a bird's chirp.
Fill the blankLevel 2
9. Scientists measure how loud a sound is in units called ____.
- decibelscorrect
- degrees
- litres
- metres
Loudness is measured in decibels; a whisper is quiet and a jet engine is very loud.
Match the pairsLevel 2
10. Match each sound to the word that best describes it.
Answer: A whisper = Quiet; A shout = Loud; A tiny bell = High; A big drum = Low
Quiet and loud describe volume, while high and low describe pitch.
Build the sentenceLevel 3
11. Build a sentence about loud sounds.
Answer: Loud sounds carry more energy than quiet sounds
Louder sounds carry more energy than quiet sounds do.
Guess the numberLevel 3
12. Loudness is measured in decibels. About how many decibels is a normal talking voice?
Answer: 60 decibels
Everyday conversation sits around 60 decibels, far quieter than a rock concert near 110.

How Sounds Are Made

Multiple choiceLevel 1
13. Sounds are made when something ____.
- vibratescorrect
- freezes
- glows
- melts
Sound is made when an object vibrates, shaking the air around it.
Choose all that applyLevel 2
14. Which of these make a sound by vibrating? Pick all that apply.
- A plucked guitar stringcorrect
- A struck drumcorrect
- A ringing bellcorrect
- A still, silent rock
A plucked string, a struck drum, and a ringing bell all vibrate, but a still rock does not.
Fact or fibLevel 2
15. Sound can travel through water.
Answer: True
Sound travels through water too, which is how whales can hear each other far away.
Fill the blankLevel 2
16. Sound travels from where it is made to your ears as invisible ____.
- wavescorrect
- colours
- shadows
- strings
Sound moves through the air as waves until it reaches your ears.
Match the pairsLevel 2
17. Match each instrument to the part that vibrates to make its sound.
Answer: A drum = The drum skin; A guitar = The strings; A flute = The air inside; A triangle = The metal bar
Every instrument makes sound when one of its parts vibrates.
Odd one outLevel 3
18. Sound can travel through all of these EXCEPT one. Which one?
- Empty space with no aircorrect
- Air
- Water
- A metal bar
Sound needs a material to travel through, so it cannot cross the emptiness of space.

Shadows and Reflections

Multiple choiceLevel 1
19. How is a shadow made?
- An object blocks light from reaching a surfacecorrect
- An object starts to glow
- Light passes right through an object
- An object gets very cold
A shadow appears when an object blocks light from reaching the surface behind it.
Fact or fibLevel 2
20. Light passes straight through a wooden door.
Answer: False
Wood is opaque, so it blocks light instead of letting it pass through.
Fill the blankLevel 2
21. When light bounces off a mirror, we call it a ____.
- reflectioncorrect
- shadow
- rainbow
- source
A reflection is light bouncing off a smooth surface, which is why you see yourself in a mirror.
Guess the numberLevel 2
22. At about what hour of the day is your shadow shortest, when the Sun is highest in the sky?
Answer: 12 o'clock
Around noon (12 o'clock) the Sun is highest, so shadows are at their shortest.
Match the pairsLevel 2
23. Match each mirror or shiny tool to how people use it.
Answer: Car mirror = See traffic behind you; Periscope = See over a wall; Bike reflector = Be seen by cars at night; Dentist's mirror = See the back of your teeth
Mirrors and reflectors bounce light so we can see things we could not see directly.
Odd one outLevel 2
24. Which surface would NOT give you a clear reflection?
- A fuzzy bath towelcorrect
- A flat mirror
- A polished car door
- A shiny metal spoon
Smooth, shiny surfaces reflect light neatly, but a rough towel scatters the light so you see no reflection.

Sources of Light

Multiple choiceLevel 1
25. What is the main natural source of light for Earth?
- The Suncorrect
- The Moon
- A street lamp
- A mirror
The Sun is a huge ball of glowing gas, and it gives Earth almost all of its natural light.
Picture questionLevel 1
26. 🕯️ Which source of light is shown here?
- A candlecorrect
- A mirror
- A cloud
- A window
A candle makes its own light with a small flame that glows.
Choose all that applyLevel 2
27. Which of these give off their own light? Pick all that apply.
- The Suncorrect
- A burning candlecorrect
- A fireflycorrect
- A shiny spoon
The Sun, a burning candle, and a firefly all make their own light, but a shiny spoon only reflects it.
Fill the blankLevel 2
28. An object that makes its own light is called ____.
- luminouscorrect
- transparent
- opaque
- silent
Luminous means glowing with its own light, like the Sun, a flame, or a light bulb.
Odd one outLevel 2
29. Which of these does NOT make its own light?
- A mirrorcorrect
- The Sun
- A candle
- A star
A mirror only bounces light back; the Sun, a candle, and a star all glow on their own.
Build the sentenceLevel 3
30. Build a sentence about how planets shine.
Answer: Planets shine by reflecting sunlight
Planets do not make their own light - they shine by reflecting sunlight.

Where these questions come from. Each unit starts as a plan of the concepts it should cover and the difficulty it should span. Questions are written against that plan with AI assistance, then checked by a validator that rejects anything without a single defensible answer, an explanation, or plausible wrong options. How we write questions sets out the whole process, and corrections are fixed in the bank and reach the site and the app the same day.

How you practise

This unit mixes 14 different question formats, so you are recalling and applying rather than recognising the same layout every time.

Build the sentence
Choose all that apply
Fact or fib
Fill the blank
Guess the number
Match the pairs
Multiple choice
Odd one out
Picture question
Put in order
Sort into groups
Spell it
True or false
Type the answer

Practise Light and Sound

125 questions across 21 steps. Start with step one and crawl at your own pace.

Play this unit

Read about Light and Sound

Explainers from our blog on what this unit covers. Each one ends with real questions from the bank.

More units in Science

See all 18 units in Science →