Lesson 19 · Science · Conservation of matter
Step 1 of 4
Find the wrong step
Your lessonConservation of matterCore
The Ice-Cube Mass Mystery
A sealed container holds 100 grams of ice. The ice melts, but nothing can enter or leave.
- Before
- 100 g of ice
- Container
- Sealed the whole time
Your question
What mass of water should remain inside after the ice melts?
Lumi’s answer: “About 80 grams, because solid ice loses mass when it becomes liquid.”
1
Step 1 of 4
Find the wrong step
Find where the reasoning first breaks
Start with Step 1 and move downward. Choose the first line that stops making sense.
Later lines may be wrong too. Pick the first mistake.
Lumi’s work
These lines form one solution. Read them from top to bottom.
- 1
The ice changes from solid water to liquid water.
- 2
The container stays sealed while the ice melts.
- 3
No water can enter or leave the container.
- 4
Because the solid shape disappears, less than 100 grams remains.