Count all three states
Ice, liquid and vapor together always total twelve grams.
Closed-Jar Matter Tracker
Move water among ice, liquid and vapor while keeping a sealed-jar total constant.
Grades 3–5 · Chemistry
Your goal
Keep the jar sealed and arrange its water as 0 g ice, 12 g liquid and 0 g vapor. What happens to the 12 g total?
Reduced motion is on. The controls still update the scene.
The water is 12 g ice, 0 g liquid and 0 g vapor. The sealed jar still contains 12 g of water. Vapor spreads out, but it does not leave the jar or stop having mass.
Each large symbol represents 3 g of water. Vapor symbols make an invisible gas visible for learning. This model tracks matter rather than temperature, energy, pressure or phase equilibrium; any requested transfer with enough source matter is allowed. The jar is always sealed, and its mass is removed from the scale reading.
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Learn with Closed-Jar Matter Tracker
Melt, freeze, evaporate, and condense water inside a jar that always stays sealed. Closed-Jar Matter Tracker gives elementary students a visible inventory for solid, liquid, and gas while a scale keeps the total in view. Each action moves three grams from one state to another, so students can follow matter instead of treating disappearing liquid as lost material. Guided goals ask learners to build different combinations and explain the unchanged total. Vapor symbols make an invisible gas easier to count without suggesting that real water vapor is visible.
What to look for
Transfer rather than remove
Every button takes three grams from one state and adds it to another.
Keep the boundary sealed
Gas stays part of the system even when liquid is no longer visible.
For teachers and curious learners
Account for gas as well as solids and liquids in conservation of matter. Ask students to predict what will happen, change one setting, and explain what they observe. Learn gives a starting point. Practice and Challenge offer new goals with the same scene.
Twelve grams of water transfer in three-gram increments. The jar mass is subtracted. This inventory model does not calculate energy, temperature, pressure or equilibrium, and allows any transfer with enough source matter.