Today is rung 4 of 6 on this topic
Properties of matter, and changes you can undo
Can do: Describes materials by property, and knows which changes can be reversed and which can't.
Why it matters
Reversible versus irreversible is the child's first grip on chemical change, and it can be tested entirely in a kitchen.
What it looks like when it's wobbly
Thinks melting and burning are the same kind of change because both involve heat.
⏱️ Two-minute check
"If we melt an ice cube, can we get it back? What about burning a piece of toast?"
Solid looks like: Yes for the ice, no for the toast, with some reasoning.
The full activity for this topic · 20 minutes
Kitchen Changes
- 1Melt an ice cube and refreeze it. Note that it comes back.
- 2Melt chocolate and let it set. Same idea, different material.
- 3Cook an egg. Ask whether they can un-cook it. Let the answer land.
- 4Sort every change into two columns: can undo, can't undo.
- 5Predict a new one before testing it — toast, or dissolving salt in water.
If it's too hard
Just ice and toast, and the two-column sort.
If it's too easy
Dissolving: is salt in water reversible? Boil some off and find out.
Say this
"Can we get it back exactly as it was? That's the question that sorts these two piles."