Temperature
At what temperature does ice become liquid? (melting point of water)
0°C
How does the light travel?
In straight lines
Explain how the light travels when a girl sees a tree.
The Sun -> tree --> girl
Explain what transparent, translucent, and opaque mean.
Transparent objects allow ALL the light to pass through.
Translucent objects only allow SOME of the light to pass through.
Opaque objects do not allow any light to pass through.
The Earth completes one rotation around its axis every ____ hours.
24
What is the boiling temperature of water?
100°C
Name 2 examples of natural light sources and 2 examples of artificial light sources.
Natural: the Sun, fireflies
Artificial: smartphone, candle
Why can't we see anything in the dark?
Because we need light to see things. Light reflects off objects and we can see them.
Make an example for each of these:
- transparent material
- translucent material
- opaque material
Any correct answer is accepted.
The Earth revolves around the Sun. It takes _____ days to complete one revolution.
365 and 1/4
Name three temperature scales.
Celsius, Kelvin, Fahrenheit
Which surfaces reflect light the best?
Draw a diagram to show how light travels when a boy looks at himself using a mirror.
You should show that the light is coming from a light source to the boy, then the light is reflected to the mirror and is reflected back again to the boy.
Light source --> boy --> mirror --> boy
How is a shadow formed?
Shadows form when _______ from _________ is _______ by an _______ object.
Shadows form when a light from a light source is blocked by an opaque object.
How do we call each of these?
1. a line between the Earth and the sky
2. a line that divides the Earth into two hemispheres
1. horizon
2. equator
What is condensation?
How can we prove that light travels in straight lines?
Many answers can be accepted. For example, we can use a straight pipe and a bent pipe and look through them at something. We won't see anything with a bent pipe.
When we look at red roses, which colours are absorbed? Which colours are reflected?
Red is reflected, other colours are absorbed.
There are five shadow shades, from 0 to 5.
Tell me what shadow shades are formed from transparent objects?
What about translucent objects?
What shades do opaque objects give?
Transparent materials give shade 1 or no shadow.
Opaque materials give shade 5 or total shadow.
Translucent materials give partial shadows with shades 2, 3 or 4.
Name TWO reasons why we have seasons.
1. the tilt of the Earth's axis
2. revolution around the Sun
Who invented the first thermometer?
Gabriel Fahrenheit
How does the light travel when it reflects, for example, from a mirror? (there is a certain rule)
Light reflects from a mirror at the same angle as it arrives.
A periscope is an instrument that uses two mirrors to see what's above.
Explain why shadows are great evidence that light travels in straight lines.
When an object blocks light, it creates a shadow because the light can't bend around the object.
If light could curve or bend, shadows wouldn't have sharp edges—they’d be blurry or not form at all.
At the Equator, there is no big difference between seasons. Why?
At the Equator, the sun is almost always directly overhead.
This means temperatures stay warm all year.