Conservation of Matter
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
The law of conservation of matter states the total matter present does not detectably change during a physical or chemical change.
Show
When sugar ferments into alcohol and carbon dioxide, the total mass of the products equals the mass of the starting ingredients.
Watch for
A drying puddle seems to show matter vanishing; sealed, so the vapor cannot escape, measuring confirms the total mass unchanged.