4th grade · Science · Unit 2 of 11
Light
Sources, shadows, reflection and refraction
What your child practices
Natural and artificial light, things that make light and things that reflect it, shadows, transparent, translucent and opaque materials, mirrors, refraction, and how light technology affects people and wildlife.
New York State Learning Standards learning standard: 4-PS4-2 · light reflecting from objects into the eye lets us see them
How we explain it
Children can open this short lesson before they practice.
- Light sources make their own light, like the Sun or a lamp. The Moon only reflects sunlight.
- Light travels in straight lines, so it can't go around corners. Blocked light makes a shadow.
- Mirrors reflect light. Light bends (refracts) when it passes between air, water or glass.
- You see an object when light from it enters your eyes.
Example: Why does a pencil in a glass of water look bent? Light from the pencil passes from water into air. Light bends when it moves between materials. This is refraction. Answer: the light refracts (bends)
Light in New York
In the New York State Learning Standards, this is unit 2 of 11 in 4th grade Science, after Sense & Respond and before Sound.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
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
Does it give off a lot of heat with its light? Tap an item, then tap its basket.
Sort into: 🔥 light and lots of heat · 🧊 light and little heat
- ✨a firefly
- ☀️the Sun
- 💡an LED bulb
- 🟢a glow stick
- 🔥a campfire
- 💡an old-style bulb
🔥 light and lots of heat: the Sun, a campfire, an old-style bulb · 🧊 light and little heat: a firefly, an LED bulb, a glow stick
Hint: The Sun, flames and old-style bulbs give off lots of heat. LEDs, glow sticks and fireflies give off light with very little heat.
Question 2
Why can we see the Moon?
🌙- it is on fire
- it makes its own light
- it glows in the dark by itself
- it reflects light from the Sun
it reflects light from the Sun
Hint: The Moon does not make light. It bounces sunlight toward Earth.
Question 3
Light travels in a straight path. How does this explain why you can't see around a corner?
🧱- corners make light
- light turns green
- light stops at corners
- light from behind the corner cannot bend to reach you
light from behind the corner cannot bend to reach you
Hint: You need light to travel straight to your eye.
Question 4
A black T-shirt gets hotter in the sun than a white one. Why?
👕- black reflects more light
- black absorbs more light energy
- black makes light
- white absorbs more light
black absorbs more light energy
Hint: Dark colors absorb more light.
Question 5
Which surface absorbed the most light energy?
Temperature after 10 minutes in the Sun (°C) - black paper
- white paper
- foil
black paper
Hint: It got the warmest.
Question 6
What color of clothing would keep you coolest in the sun?
👕- dark brown
- dark blue
- black
- white
white
Hint: White reflects most of the light.