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Science Launch G5 / Week 01 / Wednesday
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Week 01 · Too Small to See

Wednesday

Investigation: The squeeze test
// Matter is made of tiny particles
⏱ about 15 min

Wednesday: Investigation: The squeeze test

Rocket lines up two plastic bottles on the workbench. One is full of water. The other holds only air.

"Both caps are on tight," he says. "Let's see what happens when I squeeze."

Raven stops his hand. "Wait. First we predict," she says. "Which bottle will squeeze in more?"

Rocket grins. "Prediction first. Got it."

Nova blinks her eyes. "Think about yesterday's dots," she says. "Which particles have the most empty space between them?"

What you need

  • Two empty plastic bottles of the same size, with caps
  • Water
  • A towel for drips
Safety first
Use plastic bottles only, never glass.
Ask a grown-up to help fill one bottle with water.
Work over a sink or towel, and wipe up spills so nobody slips.
Nothing goes in your mouth.

Steps

  1. Fill one bottle all the way to the top with water.
  2. Screw its cap on tight.
  3. Leave the other bottle full of air and screw its cap on tight.
  4. Make your prediction below.
  5. Squeeze the air bottle with both hands. Notice how far it goes in.
  6. Squeeze the water bottle the same way. Notice how far it goes in.
MAKE A PREDICTION
  • Read the question.
  • Tap your answer.
Which capped bottle do you predict will squeeze in more?
BottleDid it squeeze in a lot, a little, or almost not at all?
Air bottle
Water bottle

Scientists found the same thing you probably did. Gas particles are very far apart, so they can be squeezed into a smaller space.

Liquid particles are already close together. There is very little room to push them closer.

Which bottle has particles with more space between them? Type air or water.
WHY THIS EXERCISEThe air bottle squeezes in because gas particles are far apart. That is evidence that air is made of particles.

Evidence from the squeeze

The air bottle squeezed in. The water bottle hardly moved.

That difference is evidence about particles you cannot see.

Gas particles have lots of space between them. Liquid particles are already close.

SQUEEZE THINKING
  • Read the question.
  • Tap your answer.
Why did both bottles need to be the same size?
Why is a bottle full of water hard to squeeze?
StatementTrue or false?
Gas can be squeezed into a smaller space.?
The squeeze test is evidence that air is made of particles.?
You predict after you do the test.?
WHY THIS EXERCISEScientists predict first, then test, then use the evidence.

You just used a test to find evidence of something invisible. That is real science. Tomorrow we will make sugar seem to vanish.

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