Light Flashcards
(25 cards)
What is a light source?
A light source is something that makes and gives off its own light.
Name 3 natural sources of light.
The Sun, stars, and fire are natural light sources.
Is the moon a light source? Why or why not?
No — the Moon reflects sunlight but doesn’t produce its own light.
What is reflection?
Reflection is when light bounces off a surface.
What kind of surfaces reflect light well?
Smooth, shiny surfaces like mirrors or polished metal reflect light well.
What does it mean if something is transparent?
Transparent objects let all light through, so you can see clearly.
What does translucent mean?
Translucent objects let some light through, but not clearly (e.g., frosted glass).
What does opaque mean?
Opaque objects block all light — you can’t see through them.
Why does a shadow form?
Shadows form when an opaque object blocks light.
What happens to a shadow when the light source moves closer?
The shadow gets larger when the light source is closer.
Why do shadows change length during the day?
Because the Sun moves across the sky, changing the angle of light hitting objects.
What direction does light travel?
Light always travels in straight lines.
What is refraction?
Refraction is when light bends as it passes from one material into another (like air to water).
Why does a pencil look bent in water?
The light bends (refracts) as it slows down entering water, making the pencil look bent.
How does a prism affect light?
A prism splits white light into a rainbow (the spectrum) by bending each colour differently.
What is white light made of?
White light is made of all the colours of the visible spectrum.
Why do we see different colours?
We see different colours depending on what wavelengths an object reflects — a red object reflects red light.
What happens to light when it hits a black object?
It absorbs almost all the light, turning it into heat.
What happens when light hits a mirror?
It reflects the light at the same angle it came in — this is called the law of reflection.
What’s the difference between reflection and refraction?
Reflection bounces light, refraction bends it.
How do sunglasses work?
Sunglasses block or filter out some light, often UV light, to protect your eyes.
Why is the sky blue?
Because blue light scatters more in the atmosphere than other colours.
Why do we see lightning before we hear thunder?
Because light travels faster than sound.
Why are lasers different from regular light?
Lasers produce a very focused, narrow beam of one colour and wavelength.
