DIRECTIONS: Each of these is hard to explain if matter is solid all the way through. Say why.
#
What you can watch
How would this work if matter were solid all the way through?
How does it work if matter is made of separate particles?
1.
A cake is baking. Ten minutes later you can smell it upstairs — and every door in the house is shut.
2.
A spoonful of sugar is stirred into a completely full glass of water. It does not overflow.
3.
1 liter of water is poured into 1 liter of rubbing alcohol. The mixture measures about 1.93 liters.
The third one: nothing spilled or evaporated, yet 2 liters became 1.93, every time.
What Is Between Them?
Grade 6 · Particles · Page 2 of 3
DIRECTIONS: Four children drew the particles in a glass of water. Which one is right?
The model: all matter is tiny particles, always moving, with
nothing at all between them (not air, not water).
Which drawing shows the model correctly?
Take the other three one at a time. For each, say in a sentence what it gets wrong.
In drawing A the particles float in gray water. Ask the child who drew it: what is the gray stuff made of? Why is that question so awkward to answer?
Now use the model on the strangest observation from page 1. Where did the missing 70 milliliters go? Nothing was lost.
Watch Them Move
Grade 6 · Particles · Page 3 of 3
DIRECTIONS: Drop one drop of food coloring into a still glass of cold water and one of hot. Do not stir. Time each.
Glass
Time until the color is spread evenly
cold water
hot water
Which spread faster, and roughly how much faster?
Nobody stirred either glass. So what moved the color through the water?
What does the difference between the glasses tell you about the particles in hot water?
A friend says the color spread because it was heavier than the water and sank. Describe what you would have seen if he were right — and say whether that is what you saw.