Grade 8 · Science · Unit 12 of 22
How Light Behaves
Reflection, refraction and the ray model
What your child practises
Light as rays that travel in straight lines, how materials reflect, absorb or transmit it, the law of reflection and why light bends (refracts) between materials.
Alberta Curriculum learning outcome: Unit C: Light and Optical Systems · transmission, reflection, absorption and refraction of light, and the ray model of light
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
A straw in a glass of water looks bent at the water's surface. Why?
- The glass is curved like a mirror.
- Water absorbs the straw.
- Light bends as it passes from water to air.
- The straw really bends.
Show answer
Light bends as it passes from water to air.
Hint: Refraction makes the straw look broken.
Question 2
Light travels in…
- curves
- zigzags
- straight lines
- circles
Show answer
straight lines
Hint: The ray model shows light as straight lines called rays.
Question 3
A ray hits a flat mirror and makes an angle of 45° with the normal. What is the angle of reflection?
answer box°
Show answer
45 °
Hint: The angle of reflection equals the angle of incidence, so it is 45°.
Question 4
What is refraction?
- the making of light
- the bending of light as it passes from one material to another
- the soaking up of light by a surface
- the bouncing of light off a surface
Show answer
the bending of light as it passes from one material to another
Hint: Light changes speed in a new material, so it changes direction.
Question 5
Frosted glass lets some light through but you cannot see clearly. It is…
- transparent
- luminous
- translucent
- opaque
Show answer
translucent
Hint: Translucent materials scatter the light that passes through.
Question 6
A ray of light strikes a flat mirror. The angle it hits at is equal to the angle it…
- absorbs at
- reflects at
- refracts at
- disappears at
Show answer
reflects at
Hint: The law of reflection: the angle of incidence equals the angle of reflection.