Lesson: Conservation of Mass

Antoine Lavoisier was one of the first scientists to state the law of conservation of mass. When he heated a sample of tin and air in an air-tight flask, tin reacted with oxygen in the air to produce tin oxide. Did the mass of the flask and its contents increase, decrease or stay the same because of this reaction?

Bread dough is placed in a baking tin and baked at . What happens to the mass of the bread?

A piece of magnesium ribbon is burned in air, producing white powdered magnesium oxide. Is the mass of the oxide greater than, less than or equal to that of the magnesium ribbon it came from?