Space, Force, and Motion
Explore gaps, attraction, and movement
What this lesson covers
Why it matters
Squeeze a bicycle pump and the air gives. Smell dinner from the next room. A drop of water beads up. Each everyday clue reveals something about the tiny particles that make up matter.
Predict first
Why can you squeeze a lot of air into a bicycle pump?
Matter is made of tiny particles that (1) have spaces between them, (2) are always moving, and (3) attract one another. These three ideas explain how matter behaves.
- There are spaces between the air particles — correct
- The air particles shrink
- Some of the air disappears
What you do
Sort each everyday clue by the particle property it reveals.
Check yourself
Perfume reaching your nose across a still room shows that particles…
Moving perfume particles spread among the moving air particles — diffusion.
You can compress a gas much more easily than a liquid because…
Gases have big gaps to squeeze out; liquid particles are already close together.
- are constantly moving — correct
- are perfectly still
- are alive
- gases have far larger spaces between their particles — correct
- gas particles are smaller
- liquid particles are sticky